Athletic Performance Monitoring Systems and Methods in a Team Sports Environment

ABSTRACT

Systems, apparatuses, and methods estimate the distance between a player and a ball by transmitting a chirp (sweep signal) to a radio tag located on the ball. During the chirp, the frequency of the transmitted signal is changed in a predetermined fashion. The radio tag doubles the transmitted frequency and returns the processed signal to a transceiver typically located on the player. The currently transmitted frequency is then compared with the received frequency to obtain a difference frequency from which an apparatus may estimate the distance. The apparatus may simultaneously receive the processed signal from the radio tag while transmitting the sweep signal.

RELATED APPLICATION DATA

This application is a continuation of co-pending U.S. patent applicationSer. No. 14/297,268 filed Jun. 5, 2014, which is a continuation of U.S.patent application Ser. No. 14/054,997 filed Oct. 16, 2013, now U.S.Pat. No. 8,784,268, which is a continuation of U.S. patent applicationSer. No. 13/531,933 filed Jun. 25, 2012, now U.S. Pat. No. 8,562,487,which is a continuation of U.S. patent application Ser. No. 12/980,800,filed Dec. 29, 2010, now U.S. Pat. No. 8,231,506, which is acontinuation-in-part of U.S. patent application Ser. No. 12/630,703filed Dec. 3, 2009, now U.S. Pat. No. 8,172,722, which claims prioritybenefits based on: (a) U.S. Provisional Patent Application No.61/200,953 filed Dec. 5, 2008, and (b) U.S. Provisional PatentApplication No. 61/186,740 filed Jun. 12, 2009. These earlier patentapplications are incorporated herein by reference in their entireties.

FIELD OF THE INVENTION

The present invention relates to systems and methods for monitoringplayer performance during athletic activities (e.g., during a game, apractice session, a workout, etc.), including team oriented athleticactivities. Such systems and methods may be useful for evaluatingperformances of one or more players in various team sporting activities,such as soccer, basketball, American football, hockey, rugby, fieldhockey, lacrosse, baseball, cricket, volleyball, badminton, and thelike. The systems and methods may be used by the individual as ameasuring stick and motivation to improve, as well as by coaches ortrainers.

BACKGROUND

Many systems are available for measuring features of athleticperformance. For example, many gyms and fitness centers are equippedwith specialized systems that help track a user's use of the machines(e.g., card readers, RFID equipment, etc.). The usage data may beautomatically generated and downloaded to a central computer system andmade available for the athlete's review. One disadvantage of suchsystems is that their use is confined to use with specialized equipmentwithin the “four walls” of the gym or fitness center.

The NIKE+™ athletic performance monitoring system (available from NIKE,Inc. of Beaverton, Oreg.) provides a convenient system and method thatallows individuals to measure and collect data relating to ambulatoryexercise, such as walking or running. Data collection using a NIKE+™system is not confined to any specific geographic location. Rather, thesystem can be used at any desired locations, both indoor and outdoor.

Not all personal exercise and athletic endeavors, however, are limitedto walking and running. Many individuals participate in team games, suchas soccer, basketball, football, and the like. At present time, there isno easy or convenient system that is useful to automatically collect,compile, and store data that accurately and empirically depicts aplayer's efforts when participating in these team sports. Such systemswould be useful to help a player gauge his or her performance, to help aplayer identify areas where improvement may be achieved, and to help aplayer recognize when improvement has been achieved. Additionally, suchsystems would be useful tools for coaches and trainers, to help themascertain each individual's strengths and weaknesses and to help themfield the best combination of players for a given game situation (e.g.,a “scoring” team, a “defense” team, etc.). Moreover, such systems couldprovide enormous motivation for the athlete by enabling the athlete (orothers) to set performance goals and/or challenges.

SUMMARY OF THE INVENTION

The following presents a general summary of aspects of the presentinvention in order to provide a basic understanding of the invention andvarious example features of it. This summary is not intended to limitthe scope of the invention in any way, but it simply provides a generaloverview and context for the more detailed description that follows.

Aspects of this invention relate to systems, methods, andcomputer-readable media with computer-executable instructions storedthereon for performing methods and/or operating user interfaces relatingto the monitoring of player performance during athletic activities(e.g., during a game, a practice session, a workout, etc.), includingteam oriented athletic activities.

Additional aspects of this invention relate to systems and methods forsensing and monitoring various athletic performance metrics, e.g.,during the course of a game, a practice, a training session, trainingdrills, and the like.

Systems in accordance with at least some examples of this invention mayinclude systems for monitoring performance parameters of one or moreathletes in a team sport setting. Such systems may include one or moreof: (a) a sensor system for monitoring one or more of: (i) a firstparameter correlated to a first player's movement speed during a firsttime period, (ii) a second parameter correlated to a determination ofwhen the first player possesses the ball and when the first player doesnot possess the ball during the first time period, and (iii) a thirdparameter correlated to the first player's ball transfer speed, force,or power during the first time period; (b) a data storage system forstoring data collected by the sensor system relating to the first,second, and third parameters; (c) a processor system for receiving andprocessing data stored in the data storage system; and (d) an outputdevice for outputting user perceptible output including athleticperformance metric information based on the collected and stored data.

As some additional examples, athletic performance monitoring systemsaccording to at least some examples of this invention may include: (a)at least one sensor system selected from the group consisting of: aRADAR-based sensor system, a radio or radio frequency based sensorsystem, a global positioning satellite based sensor system, a magnetbased sensor system, a magnetic coil based sensor system, a pressuresensor system, an accelerometer sensor system, a gyroscope based sensorsystem, a time sensor or clock, and a compass, wherein at least one ofthe at least one sensor system is provided in or on an article ofapparel, an article of footwear, a ball, or a hockey puck; (b) means forreceiving output from the at least one sensor system; and (c) processingmeans program and adapted to determine or sense, based on the outputreceived at the means for receiving, data relating to at least oneevent, metric, or feature selected from the group consisting of: aplayer receiving possession of the ball or puck; player possession ofthe ball or puck; a player's speed while in possession of the ball orpuck; one or more characteristics of dribbling the ball; a knock on andsprint event; close control of the ball or puck; dribble footdistribution; control of an incoming ball or puck; a one touch passevent; a tackle avoided event; a successful tackle event; a skin event;a ball or puck possession or proximity heat map; a player intensitymetric; boot kick zone information; ball or puck flight pathdistribution or information; longest kick or hit information; ball orpuck flight elevation angle information; kick type distributioninformation; kick or shot power information; kick or pass styleinformation; kick or shot power information at a predetermined thresholdmovement speed; pass accuracy information at a predetermined thresholdmovement speed; volley information; a free kick award event; informationdistinguishing a free kick from a penalty kick; a set piece event; a setpiece save event; information for determining whether a set piece kickis on goal; player movement direction information based on body angle; aplayer turn in event; a player turn in event when in possession of orproximity to the ball; player movement direction or type; informationregarding an amount of time a player spends on his or her toes; playerposturing or player facing direction; man-to-man opposing positioninformation; information relating to a player's ability to drawopposition; information regarding a player's speed in breaking away fromdefensive players; a successful pass event; a pass interception event; agive and go event; information relating to a ball or puck pass thatpasses in proximity to a defensive player but continues on to complete asuccessful pass; pass direction distribution information; pass playerdistribution information; information indicating an out of bounds event;information indicating an intentional out of bounds event; informationidentifying a goal keeper; information identifying a scored goal;information identifying a save; information identifying a keeper parryevent; information identifying a keeper parry event with respect to aball speed above a predetermined threshold amount; informationidentifying a keeper advance or tackle event; information identifying aplayer dive or a player jump event, and optionally, a jump heightassociated with the jump event; information identifying a drop kickevent; information identifying a shot on goal that goes out of bounds;information identifying a shot on goal; an automatic pick of teamcaptains; an automatic pick of team goal keepers; an automatic pick ofteams; information indicating a game start; information forautomatically identifying a direction of play for a team or anindividual player; information for automatically identifying anindividual player's teammates or an entire team based on passdistribution information; information for automatically identifying anindividual player's teammates or an entire team based on playerorientation; information for automatically identifying an individualplayer's teammates or an entire team based on an object's orientation,wherein each player carries an object that is oriented in a firstpredetermined manner to indicate players on one team; teamidentification using pre-game ball proximity or passing information;information regarding magnetic characteristics of a ball; ball jugglinginformation; ball pressure information as a function of magnetic fieldstrength associated with the ball; ball proximity to an article ofapparel; information for changing a state of magnetic fluid contained ina shoe based on proximity to a ball or puck; information for change astate of an article of protective gear based on proximity to a foot;information relating to running state based on magnetic properties of anarticle of footwear; information regarding entering a playing fieldbased on sensing a magnetic field; ball possession time informationbased on reaction of a magnetic switch sensor states within a shoe to amagnetic field generator within a ball or puck; information relating toa player on-field location heat map; information relating to playerexplosiveness; and information relating to whether a ball is beingthrown or kicked.

Additional aspects of the invention relate to estimating the distancebetween a player and a ball by transmitting a chirp (that may bereferred as a sweep signal) to a tag located on the ball. During thechirp, the frequency of the transmitted signal is changed in apredetermined fashion. The tag doubles the transmitted frequency andreturns the processed signal to a transceiver typically located on theplayer. The currently transmitted frequency is compared with thereceived frequency to obtain a difference frequency from which anapparatus may estimate the distance and the velocity. The apparatus maysimultaneously receive the processed signal from the tag whiletransmitting the sweep signal.

Additional aspects of this invention relate to methods of operatingathletic performance monitoring systems of the types described above, aswell as to athletic performance monitoring methods that determine orsense data relating to at least one event, metric, or feature describedabove, e.g., using the various systems described above. Still additionalaspects of this invention relate to user perceptible output systems,including graphical user interfaces displayed on computer devices, thatprovide output information to users of systems and methods according tothis invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and not limitedin the accompanying figures, in which like reference numerals indicatethe same or similar elements throughout, and in which:

FIG. 1 generally illustrates the components and features of one exampleathletic performance monitoring system in accordance with thisinvention;

FIGS. 2A through 2E illustrate example features of various products thatmay be used in athletic performance monitoring systems and methods inaccordance with this invention;

FIG. 3 illustrates a schematic view with a more detailed depiction ofcertain components of FIG. 1;

FIGS. 4 and 5 illustrate features of an alternative example athleticperformance monitoring system in accordance with this invention;

FIGS. 6 and 7 illustrate various potential features useful indetermining ball “possession” or ball “proximity” in accordance with atleast some examples of this invention;

FIGS. 8A through 8C illustrate variations in radio frequencyidentification (“RFID”) systems that may be used for “proximity” or“possession” determinations in athletic performance monitoring systemsand methods in accordance with this invention;

FIG. 9 illustrates example features and components of a semi-passiveRFID based “proximity” or “possession” determination system that may beused in systems and methods in accordance with this invention;

FIG. 10 illustrates example features and components of a digital radiopacket based “proximity” or “possession” determination system that maybe used in systems and methods in accordance with this invention;

FIG. 11 illustrates an example passive frequency doubler system that maybe used in “proximity” or “possession” determination systems and methodsin accordance with this invention;

FIG. 12 illustrates example features and components of a RADAR based“proximity” or “possession” determination system that may be used insystems and methods in accordance with this invention;

FIG. 13 is a diagram that aids in the discussion of multi-playerconcurrent usage of systems and methods of the invention and “datacollisions;”

FIG. 14 is a diagram that aids in the discussion of multi-playerconcurrent use of systems and methods in accordance with this invention;

FIGS. 15-18 illustrate example features of user interfaces that may beprovided by systems and methods according to examples of this invention;

FIGS. 19A and 19B illustrate various features that assist in explainingdifferences in detector response for throwing actions v. kicking actionsin accordance with examples of this invention;

FIG. 20 assists in explanation of detection and/or measurement of an“explosiveness” metric in accordance with examples of this invention;

FIG. 21 assists in explanation of detection and/or measurement of anacceleration metric in accordance with examples of this invention; and

FIGS. 22 through 94 assist in explanation of detection and/ormeasurement of various athletic performance metrics, features, and/orother features of systems and methods in accordance with examples ofthis invention.

FIG. 95 shows an exemplary embodiment of a passive frequency doubler tagthat may be embedded on a puck or ball in accordance with embodiments ofthe invention.

FIG. 96 shows a two-element sinuous antenna that may be incorporatedwith a frequency doubler tag in accordance with embodiments of theinvention.

FIG. 97 shows an antenna plot for a two-element sinuous antenna at 2.45GHz in accordance with embodiments of the invention.

FIG. 98 shows an antenna plot for a two-element sinuous antenna at 4.8GHz in accordance with embodiments of the invention.

FIG. 99 shows a crossed magnetic slotted dipole that may be incorporatedwith a frequency doubler tag in accordance with embodiments of theinvention.

FIG. 100 shows an antenna plot for a crossed magnetic slotted dipole at2.45 GHz in accordance with embodiments of the invention.

FIG. 101 shows an antenna plot for a crossed magnetic slotted dipole at4.9 GHz in accordance with embodiments of the invention.

FIG. 102 shows a turnstile dipole that may be incorporated with afrequency doubler tag in accordance with embodiments of the invention.

FIG. 103 shows an antenna plot for a turnstile dipole at 2.45 GHz inaccordance with embodiments of the invention.

FIG. 104 shows an antenna plot for a turnstile dipole at 4.9 GHz inaccordance with embodiments of the invention.

FIG. 105 shows a system for a frequency doubler tag in accordance withembodiments of the invention.

FIG. 106 shows a relationship between the range and signal strength inaccordance with embodiments of the invention.

FIG. 107 shows a flow chart that may be performed by the system as shownin FIG. 105 in accordance with embodiments of the invention.

The reader is advised that the various parts shown in these drawings arenot necessarily drawn to scale.

DETAILED DESCRIPTION

The following description and the accompanying figures disclose featuresof systems, methods, computer-readable media, and user interfaces inaccordance with examples of the present invention.

I. General Description of Systems, Methods, and User Interfaces inAccordance with this Invention

Aspects of this invention relate to systems, methods, andcomputer-readable media with computer-executable instructions storedthereon for performing methods and/or operating systems and/or userinterfaces relating to the monitoring of player performance during anathletic activity (e.g., during a game, a practice session, a workout,etc.), including team oriented athletic activities.

Systems in accordance with at least some examples of this invention mayinclude systems for monitoring performance parameters of one or moreathletes in a team sport setting (e.g., in a game, during practice, aspart of a workout program, etc.). Any desired type of team sport may beinvolved without departing from this invention, such as soccer,basketball, American football, hockey, rugby, field hockey, lacrosse,baseball, cricket, volleyball, badminton, tennis, and the like. Suchsystems may accumulate data relating to one individual on a team, tomultiple individuals on one team, and/or to one or more individuals oneach participating team.

As some more specific examples, systems in accordance with at least someexamples of this invention may include systems for monitoring athleticperformance(s) that include: (a) a sensor system for monitoring one ormore of: (i) a first parameter correlated to a first player's movementspeed during a first time period, (ii) a second parameter correlated toa determination of when the first player possesses the ball and when thefirst player does not possess the ball during the first time period, and(iii) a third parameter correlated to the first player's ball transferspeed, force, or power during the first time period; and (b) a datastorage system for storing data collected by the sensor system relatingto the first, second, and third parameters. The term “ball,” as usedherein, constitutes any item used in sporting activities that ispossessed, thrown, batted, kicked, hit, or otherwise propelled by theathletes in order to achieve a desired goal of the game. In addition toobjects that are substantially round or spherical, such as soccer balls,basketballs, field hockey balls, lacrosse balls, baseballs, volleyballs,tennis balls, and cricket balls, the term “ball,” when used genericallyherein, further includes other sport related objects, such as hockeypucks, America footballs, rugby footballs, badminton birdies, and thelike.

Systems in accordance with at least some examples of this inventionfurther may include: a processor system for receiving and processingdata stored in the data storage system; and an output device (such as anaudio device; a video device; an alpha-numeric display device; acomputer monitor; a display screen from other electronic devices, suchas cellular telephones, watches or other wrist borne devices, portableelectronic devices, etc.) for generating a user perceptible output.

Based on the sensed data, systems and methods in accordance with thisinvention may determine any desired data associated with the athleticperformance. As some more specific examples, systems and methods inaccordance with examples of this invention may determine one or more ofthe following performance metrics for one or more of the playersparticipating in an athletic activity: a player's maximum movementvelocity during a desired time period; a player's average movementvelocity during a desired time period; a player's time correlatedmovement velocity during a desired time period; a number of times that aplayer's movement velocity exceeded a predetermined threshold valueduring a desired time period; an amount of time that a player possessedthe ball during a desired time period; an amount of time that a playerwas located within a predetermined distance from the ball during adesired time period; a player's movement velocity when in possession ofthe ball during a desired time period; a player's maximum movementvelocity when in possession of the ball during a desired time period; aplayer's average movement velocity when in possession of the ball duringa desired time period; a player's time correlated movement velocity whenin possession of the ball during a desired time period; a player's balltransfer speed, force, or power (e.g., kick speed, pass speed, throwspeed, shot speed, etc.) during a desired time period; a player'smaximum ball transfer speed, force, or power during a desired timeperiod; a player's overall movement distance during a desired timeperiod; a player's overall movement distance while in possession of theball during a desired time period; a number of times that a playerpossessed the ball during a desired time period; a number of times thata player was located within a predetermined distance from the ballduring a desired time period; a number of times that a player contactedthe ball during a desired time period; one or more performance goals fora player; whether a player has achieved a performance goal; and arevised performance goal for a player.

The output system associated with systems and methods according to thisinvention may output information relating to a player's athleticperformance in any desired form, format, or manner (e.g., in any userperceptible manner). For example, the output system may output audio,video, alpha-numeric, tactile, and/or graphical information (includingthrough a graphical user interface) relating to any of the performancemetrics described above.

Methods for monitoring athletic activities of the types described abovemay include one or more of the following steps: (a) sensing datarelating to one or more of: (i) a first parameter correlated to a firstplayer's movement speed during a first time period, (ii) a secondparameter correlated to a determination of when the first playerpossesses the ball and when the first player does not possess the ballduring the first time period, and (iii) a third parameter correlated tothe first player's ball transfer speed, force, or power during the firsttime period; (b) storing the data relating to the first, second, andthird parameters; (c) calculating or determining one or more athleticperformance metrics based on the sensed or stored data; and (d)generating a user perceptible output that includes information relatingto one or more of the calculated or otherwise determined athleticperformance metrics. The performance metrics may be any of the varioustypes described above. The user perceptible output may be in any of thevarious forms or formats described above (e.g., audio, video,alpha-numeric, tactile, and/or graphical information).

When the athletic performance of multiple participants is tracked, the“time periods” for the tracking may be the same or different withoutdeparting from this invention. For example, the sensors may collect datafor each player only during the time period that the player is actuallyactively in the game (e.g., when the player is not on the bench). Thetime period(s) may span one or more games or practice sessions, or theymay involve only portions of games or practice sessions. Also, the timeperiod may involve continuous or discontinuous blocks of time (e.g., ifa player goes in and out of a game, the sensors may sense the player'sactivity over the course of the entire game as a single “time period,”but only while the player is actively involved in the game).

Additional aspects of this invention relate to generating userperceptible output relating to athletic performance metrics measuredand/or determined by systems and methods in accordance with thisinvention. In some examples, this output may be in the form of agraphical user interface generated on a computer-controlled displaydevice (such as a computer monitor, a display screen for a cellulartelephone or other portable electronic device, other audio and/or videodisplay devices, etc.). Such aspects of the invention may includecomputer-readable media (such as a computer memory, like a hard diskdrive, a portable computer memory device, and the like) includingcomputer-executable instructions stored thereon for generating agraphical user interface on a display device, wherein the graphical userinterface includes one or more of: (a) a display portion containinginformation relating to a player's movement speed during a desired timeperiod of an athletic performance activity; (b) a display portioncontaining information relating to a player's ball possession during adesired time period; (c) a display portion containing informationrelating to a player's ball transfer speed, force, or power during adesired time period; (d) a display portion containing informationrelating to a player's maximum movement speed during a desired timeperiod; (e) a display portion containing information relating to aplayer's maximum movement speed while in possession of the ball during adesired time period; (f) a display portion containing informationrelating to a number of times that a player's movement speed or powerexceeded a predetermined threshold during a desired time period; and (g)a display portion containing information relating to a number of timesthat a player possessed or contacted a ball during a desired timeperiod. Two or more of the various display portions may be displayedsimultaneously, or one may access information contained in some of thedisplay portions through interaction with an element provided in anotherof the display portions.

Given the general description of various example features and aspects ofthe invention provided above, more detailed descriptions of variousspecific examples of athletic performance monitoring systems, methods,computer-readable media, and user interfaces according to the inventionare provided below.

II. Detailed Description of Specific Examples of Features of AthleticPerformance Monitoring Systems and Methods According to the Invention

The following discussion and accompanying figures describe variousexample systems, methods, and computer-readable media withcomputer-executable instructions stored thereon for performing methods,operating systems, and generating user perceptible output relating tothe monitoring of player performance during an athletic activity (e.g.,during a game, a practice session, a workout, etc.), including teamoriented athletic activities. When the same reference number appears inmore than one drawing, that reference number is used consistently inthis specification and the drawings to refer to the same or similarparts or elements throughout.

Initially, example hardware for operating systems and performing methodsin accordance with this invention will be described. Then, a moredetailed explanation of examples of performance monitoring andperformance metric determination will be described. Example features ofuse of systems and methods in accordance with this invention in amulti-user atmosphere will be described. Additionally, features of anexample user interface for providing user feedback and information willbe described.

A. Example Hardware Systems

FIG. 1 generally illustrates features of example hardware componentsthat may be included in an athletic performance monitoring system 100 inaccordance with this invention. First, the system 100 may include one ormore sensors that are carried by the athlete 102 during the course ofthe game, practice session, or the like (generically referred to hereinas an “athletic performance” or “athletic activity”). As some morespecific examples, one or more of the athlete's shoes 104 may carry asensor 106 therein. As will be described in more detail below, the shoesensors 106 may be used, at least in part, to measure various athleticperformance metrics, such as movement speed, movement distance, on ballmovement speed, on ball movement distance, off ball movement speed, offball movement distance, ball possession time or count, kick speed, etc.The shoe based sensors also may be used to provide a record or identifythe player that kicked the ball (optionally while also using data from aball based sensor). In some example systems and methods according tothis invention, the shoe 104 based sensors 106 may measure speed anddistance in a manner akin to the measurement of speed and distance inNIKE+™ athletic performance monitoring systems available from NIKE, Inc.of Beaverton, Oreg. (e.g., pedometer based speed and/or distance typeinformation).

If desired, the foot mounted sensors 106 may transmit relevant data backto a receiver 108 also worn by the athlete 102. While the data may betransmitted in any desired manner, FIG. 1 generally illustrates awireless type transmission, as shown by transmission elements 110,transmission icons 112, and receiver element 114. Any desired wirelessor wired transmission system and method may be used without departingfrom this invention, including the use of any desired wired or wirelessdata transmission format or protocol, including the transmission systemsand protocols currently in use in NIKE+™ athletic performance monitoringsystems.

The receiver 108 receives the data from the one or more shoe mountedsensors 106 and stores this data and/or transmits it to an input system122 provided in a remote computer system 120. This can be accomplishedin real time, during the athletic performance, if desired. FIG. 1illustrates that the receiver 108 includes a transmission system (i.e.,transceiver element 114), and the actual data transmission procedure isrepresented in FIG. 1 by transmission icon 116.

The remote computer system 120 may be any desired type of computersystem, at any desired location, without departing from this invention.For example, the transmission system 114 may transmit over the internetto a remotely located server or other computer system 120, e.g., viacellular telecommunications systems or other wireless publicly orprivately available data transmission systems. As other examples, thetransmission system 114 may transmit to a sideline based or coaches' boxbased computer system 120, including to hand-held or portable computersystems 120, like those available in cellular telephones, personaldigital assistants, and the like. In this way, the coach, trainer, orathlete 102 (or others) can readily have the collected data availablefor review and use, even in real time during the athletic performance.

The on-body receiver 108 further may include one or more sensor devices118, if desired. For example, as will be explained in more detail below,the sensor device(s) 118 may constitute a body core mountedaccelerometer that may be useful in determining player acceleration,player movement velocity, player movement distance, on ball movementspeed, off ball movement speed, vertical displacement (up or down), andthe like. The on-body receiver 108 sensor device(s) 118 also may beuseful for sensing the ball, for determining metrics like ballproximity/possession time, on ball speed, on ball acceleration, off ballspeed, off ball acceleration, etc. If desired, the body core sensordevice(s) 118 may be utilized and the shoe based sensor device(s) 106may be eliminated (or vice versa). As another example, if desired, theshoe based sensor device(s) 106 may directly transmit to computer system120, without the intermediate transmission to an on-body receiver 108.

In systems and methods in accordance with at least some examples of thisinvention, the ball 130 also may include one or more sensors 132, a datatransmission system 134, or other electronic capabilities (both activeand passive). As shown in FIG. 1, the data transmission system 134 ofthe ball 130 also may transmit data to the remote computer system 120(e.g., as shown through transmission icon 136). Again, any desired typeof transmission system may be used, such as wireless transmission andwireless transmission protocols. As will be described in more detailbelow, the ball sensor system 132 may be used to provide informationuseful for determining various metrics such as ball speed, balllocation, ball possession (e.g., by ball contact with or proximity to aplayer), kick speed, kick force, and the like. The ball sensor(s) 132may include, among other things, one or more accelerometers, gyroscopes,pressure sensors (e.g., piezoelectric sensors, force sensors, etc.),RFID tags, etc. If desired, the ball transmission system 134 couldtransmit to the receiver 108 in addition to or in place of thetransmission to the remote system 120.

FIGS. 2A and 2B illustrate features of a shoe 104 that may include oneor more sensors 106 in accordance with at least some examples of thisinvention. As shown in these figures, the sole 140 of one or both shoes104 may include a centrally located housing 106 a in which sensor 106 ismounted. As noted above, this sensor 106 may be an accelerometer or apedometer based speed and/or distance type sensor (e.g., a piezoelectricsensor, a force sensor, etc.), and the mounting location and structuremay be akin to the mounting of the sensors in NIKE+™ athleticperformance monitoring systems available from NIKE, Inc. of Beaverton,Oreg. (e.g., mounted generally in the arch area of the sole 140, withina housing 106 a defined in the midsole structure and underneath a sockliner or insole member of the shoe 104). Other mounting locations,structures, and arrangements on a shoe 104 (or other foot or leg borneequipment, such as a sock, shin guard, etc.) are possible withoutdeparting from this invention.

As further shown in FIGS. 2A and 2B, the shoe 104 may include othersensors, such as sensor 106 b. This sensor 106 b (or sensors) may beprovided for other purposes, such as detection of contact with the ball130 (which may correlate to ball possession), detection of kick force,detection of foot acceleration (which may correlate to kick force, ballspeed, etc.), or the like, and it may be provided at any desiredlocation on the shoe 104 (e.g., on the exterior, within theconstruction, on or incorporated into the upper, etc.). The sensor 106 bmay be an accelerometer, a force sensor, a pressure sensor (e.g., apiezoelectric sensor), or the like. Other sensors also may be providedon one or both shoes 104 worn by the athlete 102 without departing fromthis invention. When sensors are provided on both shoes, these sensorsmay measure the same or different parameters.

FIGS. 2A and 2B illustrate that the sensor 106 b is connected to sensor106 via connection 144, and in this manner, data from both sensor 106and 106 b is transmitted to the receiver 108 via transmission system110, 112, and 114. This is not a requirement. For example, if desired,sensor 106 b could include its own data storage and/or transmissionsystem for storing data and/or transmitting it to the receiver 108 (orto another remote system, such as remote system 120). Other data storageand/or transmission arrangements also are possible without departingfrom this invention.

FIG. 2C schematically illustrates an example on-body receiver 108 thatmay be included in systems and methods in accordance with at least someexamples of this invention. The receiver 108 of this example includesthe data input device 114 that receives data transmissions from theshoes 104 or other remotely located sensors (e.g., sensors 106, 106 b,132, etc.). This remotely generated data may be stored in a memorydevice 150, further processed by a processor system 152, and/orimmediately transferred to output system 154 (e.g., for transmission toanother remote system, such as system 120). As mentioned above, receiver108 further may include one or more of its own sensors 118, such as anaccelerometer, a ball proximity detector, or other desired sensorelement.

FIG. 2C illustrates the receiver 108 having a separate input device 114and an output device 154. This is not a requirement. If desired, inputmay be received in and output may be transmitted from the receiver 108using the same system (e.g., an input/output system, such as a wirelesstransceiver). When present as a separate system, the output device 154may take on any desired form, such as a wireless transmitter (using anydesired wireless transmission technology or protocol), a computerconnection port (such as a USB port or other computer connection port),or the like.

On-body receiver 108 may take on a variety of different forms withoutdeparting from this invention. For example, FIG. 2C illustrates thereceiver 108 in the form of a clip 148 that may be attached, forexample, to the waist band of the athlete's shorts (e.g., as shown inFIG. 1). The receiver 108 also may be in the form of a wrist band, suchas a watch or other wrist borne data receiving device 160, like thatshown in FIG. 2D. Optionally, if desired, the receiver 108 may includean output device that provides feedback to the athlete 102 in real time,as the athletic performance is taking place (such as a display monitor162 for alphanumeric, video, or textual output; audio output (such asspeaker 164, headphone, ear bud, etc.); etc.), as shown in FIG. 2D. Asanother option, the output device 154 may provide output to a device forproviding real time feedback to the athlete 102 (such as a display, aspeaker, an earphone, etc.).

FIG. 2E shows an overall system similar to that of FIG. 1, except inFIG. 2E the receiver 108 is formed as part of an armband 170, which maybe worn inside the athlete's shirt or outside the shirt. Otherarrangements and mountings for sensors, such as sensors 106, 106 b,and/or 118, and/or receiver 108 (if present or necessary) are possiblewithout departing from this invention. For example, one or more of thesensor(s) or receiver may be integrated into the clothing of the wearer,such as formed in or housed within a pocket provided in the waistband ofthe shorts or elastic of the jersey, as part of a belt structure, etc.As additional examples, a player's shin guard may include a sensorand/or a receiver device (e.g., for sensing the same type of data assensed by the shoe borne sensor(s), such as step count, pedometer typespeed and distance information, accelerometer data, ball contact data,ball proximity data, kick force, etc.). As another example, the receiver108 or sensor(s) 118 could be included as part of a neckband, headband,or other apparel. Preferably, any body mounted sensors and/or receiverswill be lightweight, durable, and positioned so as to have little or noimpact on the player's performance or play and so as to have little orno possibility of injuring the player or others.

FIG. 3 illustrates additional features that may be included in systemsand methods in accordance with at least some examples of this invention.In addition to the two foot mounted sensors 106 and the body mountedsensor 118 and receiver 108, FIG. 3 illustrates additional details of anexample remote system 120 that may receive data transmitted from thereceiver 108 and/or the ball 130 (e.g., via connections 116 and 136,respectively). In addition to transmitting data from the sensors 106,118, and/or 132, transmission connections 116, 136, and/or 112 also maybe used to transmit data from the remote system 120 to the receiver 108,ball 130, and/or shoes 104, respectively (e.g., to vary or controlaspects of the sensors or other electronics provided in the receiver108, ball 130, and/or shoes 104).

The remote device 120 may be, for example, portable audio and/or videoplayers, cellular telephones, personal digital assistants, pagers,beepers, palm top computers, laptop computers, desktop computers,servers, or any type of computer controlled device, optionally acomputer controlled device that generates or displays a humanperceptible output and/or interface. The example remote device 120 shownin FIG. 3 includes a processor system 302 (which may include one or moreprocessors or microprocessors), a memory 304, a power supply 306, anoutput device 308, other user input devices 310, and datatransmission/reception system 122 (e.g., a wireless transceiver). Thetransmission/reception system 122 is configured for communication withthe receiver 108, ball 130, and/or shoe sensors 106 viatransmission/reception systems 114, 134, and/or 110 through any type ofknown electronic communication, including contacted and contactlesscommunication methods, such as RFID, Bluetooth, infrared transmission,cellular transmissions, etc. The output device 308 may constitute anydesired type of output device that includes a human perceptibleinterface and/or that generates output, such as portable audio and/orvideo players, cellular telephones, personal digital assistants, pagers,beepers, palm top computers, laptop computers, desktop computers,buzzers, vibrators, and the like. In this illustrated example, theoutput device 308 includes a user interface 308 a that may be in theform of a graphical user interface, such as an interface illustrating aninternet website page or similar graphical depiction of data orinformation.

The systems illustrated in FIGS. 1 through 3 are potentially active,real-time transmitting systems that provide data to the remote system120 as the athletic activity is taking place. This is not a requirement.For example, the system 400 of FIGS. 4 and 5 is much more passive thanthe systems of FIGS. 1 through 3. As far as the hardware systems, thesystem of FIG. 4 is similar to those of FIGS. 1 through 3 except thattransmission systems 114 and 134 are removed, and receiver 108 and ball130 function more like data loggers. More specifically, receiver 108 andball 130 store data from sensors 106, 118, and/or 132 while the athleticactivity takes place and save it for later transmission to a remotesystem 120, e.g., for post activity analysis, review, etc. If desired,even the data transmissions 112 from the shoes 104 to the receiver 108may be omitted, and the shoe based data could be stored locally with theshoe sensors 106 for later download.

Optionally, if desired, the receiver 108 may include some sort ofdisplay (e.g., like that shown in FIG. 2D) or other output device toprovide the athlete with some real-time performance feed back while theathletic performance is taking place (e.g., current speed, currentdistance traveled, minutes played, time in possession, on-ball speed,off-ball speed, a “pick up your pace” indication or other motivation orrewards, etc.).

After play is completed, the receiver 108 and the ball 130 (or anelectronic component removed therefrom including their data log) may beplugged into a remote system 120, like those described above. See FIG.5. Any type of connection system may be used without departing from thisinvention, including a wireless connection, a hardwired connection,connection via an input port (such as a USB port, or the like), etc. Theremote system 120 may be located on the sidelines, in the locker room,in a player's home, or at any desired location, and it may be portableor non-portable.

Given the above example hardware descriptions, now additional details ofexample metrics that may be measured and the use of such hardwaresystems will be described in more detail.

B. Player Acceleration, Speed, and/or Movement Distance Sensing

Movement speed is one metric that is particularly important for gaugingan athlete's performance. Systems and methods in accordance with atleast some examples of this invention may measure the player's movementspeed in various ways. For example, the sensor 106 in one or more of theathlete's shoes 104 may be adapted to measuring acceleration, speed,and/or distance information, e.g., in a manner akin to the way NIKE+athletic performance monitoring systems and other pedometer based sensorsystems monitor speed and distance information. For example, the sensor106 may be an accelerometer, a pressure sensor (e.g., a piezoelectricsensor), or other force sensor that determines each time the player'sfoot hits the ground or other data associated with foot motion. Byassuming that each foot contact constitutes a step, and by assuming eachstep covers a specific distance, the number of foot contacts may becorrelated to an overall distance the athlete traveled. If desired, thedistance for each step also may be adjusted based on various sensedfactors, such as foot loft time between ground contacts, foot impactforce, and the like, e.g., in manners that are known and used in thepedometer art. Also, by monitoring the time associated with themovements (e.g., by including a time stamp with each monitored footcontact, by tracking overall use time, etc.), the overall athlete'sspeed may be determined.

Pedometer based speed and distance measurement, however, may not alwaysprovide the desired degree of accuracy for use in many team orientedsports. For example, in soccer, football, basketball, rugby, and thelike, athletes tend to move at widely varying speeds over the course ofa game or practice session. They also tend to frequently jumpvertically, dive, and otherwise leave their feet during play. Moreover,their feet are exposed to forces from sources other than contact withthe ground, such as kicking the ball, kicking and hitting anotherobject, etc. These additional features of many team sports may limit theaccuracy of pedometer based speed and distance measuring systems.

Accordingly, systems and methods in accordance with at least someexamples of this invention may include a body core mounted speed and/ordistance measuring device. This may come, for example, in the form of anaccelerometer mounted at the core of the athlete's body, such as in awaist band mounted accelerometer sensor (e.g., a two or three axisaccelerator sensor 118, which may be included as part of receiver 108 todetermine motion in two or three dimensions). Data generated by anaccelerometer sensor 118 (i.e., the acceleration of the player at thelocation of mounting, such as the body's core or waist) may beintegrated to provide the athlete's movement speed information, and itmay be integrated again to provide the athlete's movement distanceinformation. A body mounted sensor of this type may provide moreaccurate determination of the body's motion, e.g., when moving side toside, dancing around the ball, etc. Systems and methods for measuringacceleration and integrating the data obtained from an accelerometer areknown.

Acceleration, speed, and/or distance determinations may provide usefuldata and information in several ways and for several performance metricsin systems and methods in accordance with this invention. For example,this data may be useful in determining the following metrics, which maybe of interest to participants in team sports, such as soccer,basketball, American football, rugby, and the like: overall topacceleration, average acceleration, overall top running speed, averagerunning speed, overall top running speed when in possession of the ball,average running speed when in possession of the ball, overall toprunning speed when not in possession of the ball, average running speedwhen not in possession of the ball, number of times speed exceeded apredetermined speed threshold (e.g., the number of times the athletesprinted), overall distance traveled during the game, etc. This data canhelp the players (and/or their coaches) evaluate how hard the athlete isworking, how much effort he or she is putting in to the game, how theyare improving over time, the extent of recovery from injury, etc. Thisdata also can be used to foster competition among individuals, such asteam members, e.g., to provide motivation to work harder, improve, beatthe other player's metrics, etc.

If desired, the body core based sensor (e.g., sensor 118 as part ofreceiver 108) may be the only sensor necessary for determiningacceleration, speed, and/or movement distance determination. Therefore,if desired, the foot based sensors 106 could be eliminated. Nonetheless,if desired, the foot based sensors 106 could be used to providesecondary data for speed and/or distance measurement, such as data tohelp confirm the body core based sensor data, data to adjust or correctthe body core based sensor data, and/or data to be used when the bodycore based sensor data is unavailable or seemingly unreliable.Additionally or alternatively, if desired, the shoe based sensor(s) 106could be used to help eliminate drift of the body mounted accelerometer(e.g., if the shoe based data indicates that the player is stationary,this information could be used to calibrate or re-zero (e.g., eliminatedrift from) the two or three axis body based accelerometer). Therelative difference in acceleration measurements between a body corebased accelerometer and a foot based accelerometer also may bedetermined.

As another alternative, at least some systems and methods in accordancewith this invention may include a means of detecting the player'sorientation or “mode of moving” when moving. For example, if desired, anelectronic compass or a rotational sensor may be incorporated into thesystem, e.g., to aid in detecting a player's direction of movementand/or to provide additional details regarding the characteristics ofthe player's mode of movement (e.g., running forward, running at a sidestep, running backward, etc.). An accelerometer also can provide usefulinformation regarding the direction of movement, if the accelerometerhas a predetermined orientation at the start (e.g., with one axis of atwo or three axis accelerometer facing the forward direction of motion).A determination of the amount of time or distance that a player runsforward, sideways, or backward could be a useful metric for measuringperformance, at least in some sports. Also, if desired, differentpedometer based speed and distance determination algorithms may be used,depending on the player's mode of movement (forward, backward, sideways,etc.), which may enable a more accurate determination of the player'soverall movement speed or movement distance. More specifically, onealgorithm may be appropriate for determining speed or distance (e.g.,based on foot loft time, etc.) when a player is running forward, but adifferent algorithm may be better when running sideways, and even adifferent algorithm may be better when running backward.

In one more specific example of systems and measurements in accordancewith this invention, one footpod (e.g., element 106, optionally one ineach shoe 104) measures speed and distance of each step, e.g., utilizinga 3-axis accelerometer, and the collected data may be stored on thefootpod 106 during a match or training session. A separate controller ora mobile phone (or other suitable device) may be used to communicatewith the footpod 106, e.g., for the purpose of ascertaining footpodstatus, for starting/pausing/stopping recording of a session, and forinitiating an upload of data (e.g., to computer system 120). In systemswhere a separate controller is used for these purposes, the user wouldneed to connect the controller to his/her computer to upload their data,e.g., to a website service. In the case of a mobile phone (or othersimilar device) functioning as the controller, the phone couldtemporarily store the data and/or send the data directly to a web serverwirelessly. Variations in these potential systems also are possiblewithout departing from this invention.

Notably, for purely determining an athlete's acceleration, speed, ormovement distance, no sensors, electronics, or other special featuresare needed in the ball. Therefore, if desired, a conventional ball couldbe used in such situations. In other situations and/or for measuringcertain metrics, which will be described in more detail below, it may beadvantageous to provide sensors, electronics, and/or other specializedstructures in the ball.

C. Player Ball “Possession” and “Proximity” to the Ball Detection

Another useful piece of information for many types of team sportsrelates to a player's ball possession time. This may be measured, forexample, by detecting an athlete's contact with the ball (e.g., by ahand, foot, or other body part), an athlete's close proximity to theball, or in other manners. Determination of ball possession or proximityto the ball also can be an important part of other interesting ordesired metrics, such as possession time, overall top running speed whenin possession of the ball, average running speed when in possession ofthe ball, overall top running speed when not in possession of the ball,average running speed when not in possession of the ball, number oftimes near the ball, number of ball contacts or “touches,” kick force,etc. This data can help the players (and/or their coaches) evaluate howhard the athlete is working, how much effort he or she is putting in tothe game, which players are the most effective with the ball, whichplayers work hardest to stay near the ball, the strongest defenders, theball “hogs,” etc. This data also can be used to foster competition amongindividuals, e.g., to provide motivation to work harder, improve, beatthe other player's metrics, etc.

In some team sports where the ball is held throughout at least most ofits possession, ball possession for an individual player can berelatively easy to determine, e.g., by determining which player iscontacting the ball and/or by determining how long the player held theball. One example is American football or rugby. Similarly, in lacrosse,the ball tends to rest in the head of the player's stick throughout themajority of the player's possession time. For such sports, appropriatesensors in the ball and/or on the player and/or on their equipment canrelatively easily determine who has possession and the length of time ofthat possession. As one more specific example, RFID receivers or readersin an athlete's clothing or equipment (such as gloves, a jersey, helmet,pads, stick, shoes, etc.) may be triggered by an RFID transmitter tagmounted in or on the ball, and electronics included with the athlete'sclothing or equipment may log how long each individual possession lasts.By time stamping or otherwise providing time data associated with thispossession data, the possession data could be correlated toacceleration, speed, and/or movement distance data (e.g., determined asdescribed above), to allow systems and methods in accordance with thisinvention to determine more specialized metrics, such as overall toprunning speed when in possession of the ball, average running speed whenin possession of the ball, overall top running speed when not inpossession of the ball, average running speed when not in possession ofthe ball, etc. While other players also may come in contact with theball during an individual play, this contact typically is relativelyshort term, and it typically is overlapped by and/or surrounded on eachend by contact with the main player in possession. Therefore, the datacan be easily analyzed to determine which contacts simply constituted afleeting, non-possessory contact and which contacts actuallydemonstrated possession of the ball. Alternatively, if desired, multipleplayers could be considered to simultaneously have “possession” of theball by systems and methods according to this invention (e.g., if“possession” is simply equated to any contact with the ball).

In other sports, however, continuous contact with the ball is not afeature of ball “possession.” For example, in soccer and basketball, aplayer in “possession” “dribbles” the ball to move it up and down thefield of play, resulting only in occasional contact with the ball. Theball is not typically held for long periods of time or carried for longdistances in such sports. In hockey and field hockey, the ball (e.g.,including a hockey puck) may repeatedly come into and out of contactwith the player's stick while the player in possession of the ball movesdown the field of play. Also, a player in “possession” of the ball mayonly make contact with the ball once, sometimes for only a very shorttime period (e.g., when a quick pass or shot is made). Moreover, in allof these sports (e.g., soccer, basketball, hockey, field hockey),players on the opposing teams may attempt to steal the ball or puckthroughout a player's possession. Such features of play make ball“possession” somewhat more difficult to determine using sensors.

Systems and methods in accordance with at least some examples of thisinvention may approximate a player's ball “possession” using variousfeatures of proximity of the player to the ball. While the descriptionbelow primarily focuses on possession determination in the context ofsoccer, those skilled in the art, given the benefit of this disclosure,would be capable of extending features of this description for use inother sports, such as basketball, hockey, field hockey, Americanfootball, rugby, lacrosse, and the like.

Determination of “possession” may include various features. For example,systems and methods in accordance with at least some examples of thisinvention may determine that “possession” exists whenever a playercontacts or comes within a certain threshold distance from the ball(e.g., within one meter). As illustrated in FIG. 6, such systems may bethought of as “digital” possession determining systems, where a playereither has possession or does not have possession. More specifically,when the ball 130 is within a one meter distance of the player 102(inside ring 600), the player 102 may be considered as having“possession.” When the ball 130 is more than a one meter distance fromthe player 102 (outside ring 600), the player 102 may be considered asnot having “possession.” In such systems and methods, multiple playersmay be considered as having “possession” at a single time (when eachplayer is within close proximity to the ball). When multiple playersfrom different teams are located in proximity to the ball, this also maybe considered “contested time,” as is described in more detail below.

Optionally, if desired, a positive determination of “possession” mayrequire at least one contact with the ball (and optionally, the“possession” determination may start at that contact). As anotheroption, systems and methods according to the invention may track both“possession” (e.g., requiring at least some contact and/or continuingcontact with the ball) and “proximity” (e.g., when there has not beencontact but the player is close to the ball or when a different playerhas made an intervening ball contact but the first player remains closeto the ball, etc.). If desired, a new “possession” determination may bemade each time a different player contacts the ball (although theprevious player in contact may remain close to the ball and his or her“proximity time” may continue to accumulate). As noted above,“proximity” may be simply equated to “possession” in some systems andmethods according to this invention.

“Possession” also may be considered as more of an “analog” parameter.For example, systems and methods may be produced to provide a moredetailed determination of the proximity of a player to the ball. Forexample, as shown in FIG. 7, determination of the player's distance fromthe ball may be more closely determined, to better enable adetermination of “possession.” For example, when the player 102 is veryclose to the ball 130 (e.g., within inner ring 700), that player may beconsidered in “possession” of the ball 130 (if desired, multiple playersmay have “possession” at one time). When the player 102 is relativelyclose to the ball 130 (e.g., within ring 702 but outside ring 700), theplayer 102 also may be considered to be in possession of the ball,optionally, if other parameters are met (such as if the player 102 wasthe last person to touch the ball 130 or the player 102 is the closestplayer to the ball 130, and there has been no intervening ball contactby another player, etc.). When the player 102 is somewhat close to theball 130 (e.g., within ring 704 and outside ring 702), the player 102also may be considered to be in possession of the ball 130, optionally,if other (optionally, more stringent) parameters are met (such as if theplayer 102 was the last person to touch the ball 130, the player 102 isthe closest player to the ball 130, and there has been no interveningball contact by another player, etc.). Any desired possession parametersmay be developed without departing from this invention. When the playeris too far away from the ball 130 (e.g., outside ring 704), systems andmethods according to at least some examples of the invention maydetermine that the player 102 does not possess the ball 130. Optionally,systems and methods according to at least some examples of thisinvention may determine that a player remains in “possession” of theball until a new player contact with the ball is ascertained,irrespective of the previous player's location with respect to the ball.

1. RFID Technology

One potential way of determining ball possession or proximity is throughthe use of RFID (radio frequency identification) technology. RFIDsystems use coupled energy to transmit a small amount of data between aninterrogator (also known as a “reader”) and a remote, inexpensive tag.The tag can be stationary or in motion with respect to the reader. SuchRFID systems can be categorized according to two main criteria, namely:the means of powering the tag (e.g., passive, semi-passive, or active)and the energy coupling mechanism (e.g., inductive or radiative).

FIGS. 8A through 8C schematically illustrate various RFID technologies.In the “passive” RFID system illustrated in FIG. 8A, power for both thetag and the return radio signal (i.e., the “backscattered signal” inFIG. 8A) generated by the tag are provided by energy recovered from thereader signal. Such a completely “passive” system may be advantageous inthe environment of this invention because it could eliminate the needfor a power source (e.g., a battery) on the ball. In “semi-passive” RFIDsystems, as illustrated in FIG. 8B, power for the return radio signal isprovided from recovered reader energy signal, but the tag electronicsare powered by a small battery included with the tag. The “active” RFIDsystem illustrated in FIG. 8C is really akin to a traditional radiosystem. The tag radio signal and the electronics are both powered by alocal battery provided with the tag (and the reader's electronics arepowered by its own separate power source).

Radio tag frequencies range from a few hundred MHz to several GHz. Inthis spectrum, wavelengths become comparable to the mechanical scale ofpersonal electronics and more specifically, full wavelength antennasizes. Such features allow far-field operations where power variesinversely with the square of the distance from the source.

FIG. 9 illustrates one example of the hardware and equipment that may beused in a semi-passive RFID system to detect player proximity for socceror other sports. Notably, in the system illustrated in FIG. 9, the ball130 includes the RFID tag and its associated antenna and otherelectronics, and the shoe 104 (or other article of the player'sequipment, such as a shin guard, sock, receiver 108, etc.) includes theRFID reader and its associated antenna and other electronics. Morespecifically, the ball 130 of this example carries an embedded primarycell battery, an auxiliary sensor interface, active circuitry, amodulator, passive circuitry, and an antenna. The player (e.g., the shoe104) in this example system carries a re-chargeable battery, amicrocontroller, an RF+baseband component, a low noise amp, a power amp,and an antenna. The battery assist on the ball mounted tag permits arelatively low-received power density, which effectively lowers thetransmission power required on the player (and lowers the mass of thenecessary battery and other electronic equipment to be carried by theplayer). A single ball 130 may include multiple tags on the ball (e.g.,to assure that a tag antenna is always facing the player's reader, toenable more sensitive distance measurement, such as for analogpossession determinations, etc.). RFID tag and reader equipment of thistype is conventionally known and commercially available.

Proximity detection of this type may be combined with data relating tofoot contact with the ball, if desired, to distinguish between ballpossession and ball proximity. Alternatively, as noted above, possessionmay simply be equated with proximity, if desired.

2. DPR Technology

Digital packet radio (“DPR”) also may be useful in determining ballproximity and/or “possession” (optionally, in conjunction with otherdata, such as foot and/or ball contact data) in systems and methodsaccording to at least some examples of this invention. Many NIKE+athletic performance monitoring products (available from NIKE, Inc. ofBeaverton, Oreg.) use DPR for wireless data communications (e.g., in the2.4 GHz band). DPR also is used in many commercially deployed networks,such as cellular networks, WiFi (802.11), ZigBee, and PCS. Two examplechipsets that may be used for implementing DPR based proximity and/orpossession determinations in systems and methods according to thisinvention include chipsets available from Nordic Semiconductor Inc. ofSunnyvale, Calif. and ANT Wireless of Cochrane, Alberta, Canada. Bothcompanies make ultra low-power radio silicon chipsets that can be usedin a variety of applications. The radio chipsets can be powered by astandard coin cell type battery with excellent device lifetimes.

DPR implementations for proximity and ball possession determinationsoffer low-power, high range systems and methods. FIG. 10 illustrates oneexample system. Notably, while these systems and methods are low powerand high range, they still require an active receiver end (i.e., someelectronics and/or power on the ball 130), as shown in FIG. 10. In theDPR system of FIG. 10, the ball carries an embedded power source (e.g.,primary cell battery), an embedded microcontroller, a very large scaleintegration (“VLSI”) digital radio system (e.g., a chip), and anantenna. The athlete (e.g., as part of the shoe 104 or receiver) carriesa re-chargeable battery, a microcontroller, a VLSI digital radio system(e.g., a chip), and an antenna. The DPR system may operate on anydesired frequency, such as 915 MHz or 2.4 GHz. Such hardware systems areknown and are commercially available, as noted above.

In the ball 130, the small radio and the microcontroller trigger radiobursts that send out unique identifying data packets. The trigger foreach radio burst could be periodic (e.g., every 50 ms, every second,etc.). On the other hand, the trigger could be aperiodic, such as inresponse to an actual event trigger, like motion, contact, impact, etc.These packets allow a body-worn receiver on the player 102 (e.g., inboot 104, in a body core worn element, etc.) to log received data thatdirectly correlates to how long the ball 130 spent within proximity tothe receiver. This proximity may be correlated to ball possession(optionally, if another metric is logged, such as contact between theplayer's foot and the ball 130, as determined by a shoe based sensor 106b). This is a very “digital” possession type determination system. Ifdesired, as noted above, possession may be equated to proximity.

DPR also may be used to provide more analog possession information. Insuch a system, the ball 130 may serve as the receiver, and the body worndevice may provide the bulk of the transmissions. In such as system, theball 130 would periodically listen for a radio packet broadcast from thebody worn transmitter. The body worn-transmitter could send out burstsof packets at different set output powers. The ball 130 would onlyreceive packets from the weakest transmitted signals when it is in closeproximity to the player 102. The number of signals received by the ball130 will decrease the further that the ball 130 is away from the player102 sending the signals until it is receiving only the strongest signalsor none at all. The ball 130 may respond to any received packets bytransmitting back with a unique identifier derived from the packets itreceived (e.g., an identifier indicating the transmission power). Thisarrangement allows the body worn receiver to determine how far away theball 130 is based on the weakest signal that is received at the ball 130and for which a response was sent. Alternatively, if desired, the ballcould send out the bursts of packets at different output powers and thebody worn sensor could receive these packets and determine the relativedistance between the ball and the body sensor based on the detectedsignals (and their corresponding power levels).

With DPR systems, because there is an active radio at each end, i.e., atthe ball 130 and at the player 102, the transmission power can be quitelow (and smaller than other technologies), but, as noted above, it doesrequire some power source on the ball. DRP also provides the ability todynamically vary output power, giving systems and methods in accordancewith at least some examples of this invention the ability to estimatethe range between the ball 130 and the player 102, and/or even theability for the player's system to acquire the ball outside of somepredetermined “possession” distance (e.g., one meter).

3. RADAR Technology

Ball possession and/or player proximity to the ball also may be detectedin some example systems and methods according to this invention by RADARtechnology (“RAdio Detection And Ranging”). RADAR systems use reflectedradio “ping” energy to identify and locate target objects by analyzingtheir reflected “signature.” RADAR systems do not require activetransmission in two directions, which means that the ball need notinclude an active transmitter or a power source in at least some RADARbased proximity or possession determination systems and methods inaccordance with this invention. If desired, however, RADAR based systemscould rely on an active (power utilizing) systems as part of the ball togenerate a radio “ping” for the mobile detector to recognize, or theymay in some way (e.g., actively powered or passively unpowered) enhanceor distinguishingly mark the reflected energy to ease the mobiletransponder's job of identifying the ball from the clutter of backgroundnoise, other reflections, and/or miscellaneous distortions in thesignal. Additionally, the RADAR may apply modulations and otherprocessing techniques to the transmitted energy and reflected signatureto measure other attributes of the target object, such as the velocityof the target object (e.g., by using Doppler techniques).

Passive RADAR systems, in which the ball does not include a powersource, can rely on one or more other RADAR reflection techniques toincrease the “visibility” of the reflected signal from the ball (e.g.,by increasing its gain or coherence). One example of such a techniquewould be to provide a reflective device on the ball, such as a cornerreflector. As one example, the corner reflective material could beprovided within one or more seams of the ball, or optionally in aninterior layer of the ball (if the impinging radiation is capable ofpenetrating the ball's exterior cover). Corner reflectors are known inthe RADAR and other art, and these devices reflect radiation outwardfrom the reflector in substantially the opposite direction from which itentered the reflector (i.e., directly back toward the radiation sourceand/or parallel to its incoming direction). Another example techniquewould be to provide “chaff” on or in the ball structure. “Chaff”constitutes specifically sized small pieces of RADAR reflective materialorganized in a unique pattern on the ball that is easily recognized bythe RADAR detection system. Such reflectors and chaff are well known inthe RADAR field, and are sized and shaped in suitable configurations soas to be capable of incorporation into the structure of a ball (such asa soccer ball, hockey puck, basketball, or the like). These featuresincrease the RADAR reflection signature from a ball and make the ballbetter stand out among the other RADAR radiation reflected from otherobjects in the area (such as other players, other equipment on or nearthe field, goal posts, etc.).

Another technique for helping a passive (non-powered) ball's radiationreflection signature stand out among other objects involves the use of apassive frequency doubler structure on the ball. A passive frequencydoubler works using a principle similar to “square law” detectors.Non-linear devices can generate frequency harmonics when stimulated witha signal. A diode, at small signal levels (e.g., equivalent to less than−20 dBm) has a VI relationship that is roughly I=k*V², where k is someconstant. Such a device is capable of generating a frequency harmonicthat is twice that of what is used to drive the diode, by the equation:cos(f₀)²=½+½*cos(2*f₀), where f₀ is the input frequency. This frequencyharmonic can be radiated out of the same antenna that received thefundamental frequency. Harmonics other than the doubled frequency(2^(nd) harmonic) will also be generated by the non-linear device, sothis application of detecting frequency harmonics is not limited to onlythe doubled frequency, but can also detect 3 times the frequency, 4times the frequency, 5 times the frequency, etc.

By providing a passive frequency doubler structure on the ball in such aRADAR system, the reflected radiation detector or receiver only needs tolisten for a signal at twice the carrier frequency that its associatedtransmitter radiated. This doubled frequency signal will be known to beunique to the object carrying the passive frequency doubler (i.e., theball in this arrangement). In addition, the frequency doubler alsogenerates a DC component, which may be used to power a small amount ofelectronics on the ball. These electronics could modulate the signalthat the frequency doubler radiates, essentially giving the ball aunique ID. On the other hand, the signal that is radiated can be coded(with a barker code or a pseudorandom sequence), and thenauto-correlated with the returned signal for an additional signalprocessing gain. Another simple method that may be used for processinggain would be frequency chirping.

Frequency doubler antennas of the types described above are known, asdescribed for example, in U.S. Pat. No. 4,890,111, which patent isentirely incorporated herein by reference. One example antenna 1100 asdescribed in this patent is illustrated in FIG. 11. The dimensions ofsuch an antenna may be about ⅔ of the wavelength λ of the transmittedand incident radiation frequency in the length dimension L and about ⅙that wavelength λ in the height dimension H. With such an antennaincorporated in to the structure of a soccer ball (e.g., on its exteriorsurface, between layers of the ball, within the ball interior, etc.),the mobile receiver could be configured to “listen” for a specificcarrier frequency (i.e., twice the transmitted frequency) to detect thepresence of the ball, e.g., when enough energy is present in both theforward and return path from the player mounted radiation transmitter,to allow the radiation to reach the ball and bounce back to the playermounted radiation detector. As some more specific examples, theinitially transmitted RADAR frequency may be 915 MHz, and the reflectedfrequency may be doubled to 1830 MHz. Another good candidate is 433 MHz(doubled to 866 MHz). The use of other frequencies also is possiblewithout departing from this invention.

FIG. 12 illustrates example structures that may be provided on both theball 1200 and the player 102 (e.g., as part of the player's shoe 104, aspart of receiver 108, etc.) in accordance with at least some RADAR basedproximity detection systems in accordance with this invention. As shownin FIG. 12, the ball 1200 includes an antenna structure 1202 like thatdescribed above in conjunction with FIG. 11. The shoe 104 (or otherplayer borne component) includes a rechargeable battery and/or otherpower supply, a microcontroller, a modulator, a power amp, a duplexer,an antenna, a low noise amplifier (LNA), and an analog to digitalconverter (A/D). The shoe 104 transmits radiation toward the ball 1200at a first frequency (e.g., 915 MHz), and the ball 1200 doubles thefrequency through antenna 1202 and reflects the radiation back towardthe shoe 104, where it can be detected. The ball 1200 may include pluralantennas all around the ball structure to assure that at least oneantenna faces the receiver on the player.

As an alternative, if desired, one or more RADAR radiation sources maybe independent of the player (e.g., located on the sidelines or at otherlocations, to cover the entire field, etc.). In such a system, theplayer 102 need only carry the reflected radiation detector (and itsassociated power source and electronics), and not the radiationtransmission source. The ball electronics may be configured to send outradiation only at a desired power level so that a player mounteddetector would only detect the reflected radiation from the ball when inrelatively close proximity to the ball (e.g., within 1 meter, etc.).

Various features may be provided to help prevent “packet collisions”when multiple players are using systems and methods in accordance withthis invention, e.g., to help prevent one player from detectingradiation reflected from the ball transmitted by a different player. Forexample, as shown in FIG. 13, two players, one player 102 a from oneteam and one player 102 b from the other team (or even more players),may approach the ball 1200 simultaneously. If each player is equippedwith actively transmitting RADAR or other data transmitting systems andmethods according to the invention, the various detectors or sensorscould easily read the wrong data and incorrectly determine position orproximity data. Such data “packet collisions” should be avoided toprovide more reliable and usable data for systems and methods accordingto this invention.

One way of limiting or eliminating “packet collisions” constitutes atiming plan where each player's device transmits at a random interval,with a standard mean interval in place. This would make it unlikely thatany two or more players would be transmitting at a given time inproximity to the ball, but that all players would have the same overalltransmit rate. In such a system, a player's reflected radiationdetection system could be activated only for a short time after his orher device transmits its radiation “ping” or data transmission, to helpprevent unwanted data reception and sensor activation. One potentialdownside, however, would be that such a technique could potentiallylimit a single device's ability to detect the ball quickly, due tolimitations on the average transmit rate (i.e., due to delays betweentransmissions).

Another method for limiting or eliminating “packet collisions” would beto “channelize” the devices on each player. Because the passivefrequency doubler can operate on many frequencies in a narrow band, eachplayer could use a slightly different frequency within the same broaderband. Then, each player's detector could be tuned to “look” within anarrow band around two times the transmitted frequency. Such“channelization” also could be used to distinguish one team's data fromthe other team's data during the game or other activity. Other“collision avoidance” techniques also may be utilized without departingfrom this invention. Collision avoidance features also may be used withother proximity and possession systems and methods described above, ifdesired, without departing from this invention.

4. Other Potential Proximity/Possession Detection Technology

Other sensing systems and detection arrangements may be used fordetermining proximity and/or ball possession without departing from thisinvention. For example, ultrasound based proximity detection may beutilized, particularly for very close range ball proximity detectionapplications. Ultrasound systems may work using reflected radiationtechniques similar to the RADAR techniques described above. Infraredradiation detection systems (both passive and active systems) may beutilized to detect ball proximity. Micro-Electro-Mechanical (“MEMs”)devices, such as accelerometer and/or gyroscope devices (e.g.,fabricated using semiconductor lithographic processes) also may beincorporated into a ball. Hall-effect sensing may be used with magnetsin either the ball or shoe to detect proximity, particularly for shortrange applications. The inclusion of such devices in a ball may beparticularly useful as adjunct sensors, e.g., to help determine when aball has been kicked, and optionally, which player made the kick (e.g.,by time stamping the data relating to the sensed contact in both theball data and the various player's shoe data, etc.), kick force, kickspeed, etc.

Some more specific examples are described below. One or more of thesepossession determination systems and methods may be used in conjunctionwith one or more of the speed/distance measuring systems described inmore detail above.

In some systems and methods in accordance with examples of thisinvention, a magnet may be suspended in the center of the ball 130, andthe footpod 106 may be equipped with a magnetometer (e.g., a compasssensor that measures Earth's magnetic field). This system may function,for example, by detecting small changes in the Earth's magnetic fielddue to the magnetic field emitted by the ball 130, which indicates theball 130 is within a certain distance of the player's foot (and hence acertain distance from the magnetometer of the footpod 106). From thistype of detection, physical contact with the ball and/or close proximityof the athlete to the ball may be inferred.

As another more specific example, one or more small tags may be builtinto the construction of the ball 130. A signal would be emitted by asensor/receiver on the player. When the tag in the ball 130 receives thesignal, it bounces it back at exactly double the frequency (e.g., usingthe frequency doubler features built into the ball as described above).The receipt of this doubled frequency signal by the sensor/receiver(e.g., in the footpod 106) indicates the ball 130 is within a certainrange of the sensor/receiver (e.g., dependent on the strength of theinitial signal). As some even more specific examples of this aspect ofthe invention, a sensor/receiver may be placed in both of the player'sshoes 104 and have a short required working range (e.g., about 30 cm).In this case, each detection of the ball 130 would infer a physicalcontact with the ball 130 by the player's shoe 104. Alternatively, ifdesired, a sensor/receiver may be located in just one of the player'sshoes 104 or on the player's body (such as waist-worn component 108) andhave a larger working range (e.g., about 1-2 m). In this case, eachdetection would infer proximity of the player to the ball 104, or thatthe player is in possession and control of the ball 104.

Moreover, in a similar manner to the way player-to-ball proximity may bemeasured, systems and methods according to at least some examples ofthis invention may determine player-to-player proximity. As another morespecific example, modules carried by each player may wirelesslycommunicate with one another when within a predetermined distance orrange from one another (e.g., via a peer-to-peer network) to provide anindication of player-to-player proximity.

D. Ball Motion Related Metrics

Other useful metrics for many types of team sports relates to the speedat which the ball moves during play, e.g., as a result of a kick, throw,hit (e.g., with a bat, stick, arm, foot, racket, etc.), etc. Morespecific types of metrics that may be of use include, for example, ballspeed, ball spin, linear ball speed, spin speed, spin direction, balltransfer speed (the term “transfer,” as used in this context,generically means movement of the ball due to athlete interaction, suchas a kick, throw, hit, header, etc.), ball transfer force, etc.Combining ball oriented metrics like these with various player orientedmetrics (e.g., due to shoe or player body oriented sensor data andinteraction between shoe or body oriented electronics and ball orientedelectronics, as described above) or other data, such as possession,speed, time, etc., can provide other useful information, such as theidentification of the player that kicked or otherwise propelled theball, number of ball “touches” or contacts for various specific players,goal success and credit to the appropriate player, pass attempt success(e.g., whether the pass successfully reached a player on the same team),steals, missed passes, turnovers, etc.

Providing sensors in various types of balls, such as soccer balls, isknown in the art. For example, various electronically enhanced ballsthat measure metrics, such as spin, speed, curve, trajectory, pressure,contact, and the like, are described in patent applications owned byCairos Technologies, AG and in patents naming David J. Martinelli as theinventor. These patents include: U.S. Pat. No. 6,073,086; U.S. Pat. No.6,157,898; U.S. Pat. No. 6,148,271; U.S. Pat. No. 6,151,563; U.S.Published Patent Appln. No. 2007/0191083; U.S. Published Patent Appln.No. 2007/0059675; U.S. Published Patent Appln. No. 2007/0060425; U.S.Published Patent Appln. No. 2007/0299625; U.S. Published Patent Appln.No. 2008/0085790; U.S. Published Patent Appln. No. 2008/0084351; U.S.Published Patent Appln. No. 2008/0088303; U.S. Published Patent Appln.No. 2008/0090683; PCT Published Patent Appln. No. WO2008/080626; PCTPublished Patent Appln. No. WO2008/104,247; and PCT Published PatentAppln. No. WO2008/119479. Each of these patent documents is entirelyincorporated herein by reference. The various ball oriented sensors orother electronics or structures described in the possession/proximitydiscussion above may be incorporated into a ball structure in the samemanner as described in these various patents and publications.

E. Example Team Features

As illustrated in FIG. 13 (and as alluded to above) and FIG. 14, systemsand methods in accordance with this invention are not limited for usewith a single player. Rather plural players, optionally on both teams,may be equipped with active transmitters and/or receivers that interactwith the transmitting, receiving, and/or reflecting equipment providedwith the ball 130 or 1200. When plural players on a team are equippedwith appropriate electronic equipment as described above, it can bedetermined when the ball 130, 1200 moves from one team member toanother. Such systems and methods can be useful for providing variousteam metrics, such as team possession time, passing streaks andefficiency, pass accuracy, turnovers, steals, tackles, etc. All data(e.g., from the players on both teams, from the ball 130, 1200, etc.)can be transmitted to a single remote computer system 120, oroptionally, if desired, to different remote computer systems 120 (e.g.,one for each team, one for each player, etc.). As yet another example,if desired, the data can simply be logged during the game or practicesession (as described in conjunction with FIGS. 4 and 5 above) and laterdownloaded or otherwise accessed for use by the individual players,coaches, etc. The various player's data also could be intercommunicatedto one another via peer-to-peer networking so that players could compareperformances quickly and easily, e.g., on the sidelines, in the lockerroom, etc.

Team oriented metrics also allow team players and coaches to look atboth the individual and team data and determine various features orcharacteristics of play, such as which players play best together, thestrengths and weaknesses of individuals, the strengths and weaknesses ofvarious groupings of players, who is ball “hogging,” who isinsufficiently involved in the game, who is loafing, etc. The coachesand/or team members can evaluate the data in real time (e.g., on thesidelines, in the coach's box) during the game or practice session tobetter understand whether a combination of players is working (or,potentially, to discover an injury or other need for substitution bynoting that a player's performance has suddenly fallen off). Also, theteam data can be used to motivate the individuals to challenge oneanother and/or to motivate them to make efforts to improve the overallteam statistics.

F. Example Website Features

Additional aspects of this invention relate to the presentation of datato the player, coach, trainer, or other person(s). Such systems help theplayer measure and track his or her capabilities, mark improvements overtime, determine areas that require additional work, etc. Data can becollected over single games, portions of games, single practices,portions of practices, multiple games (or portions thereof), multiplepractices (or portions thereof), multiple seasons (or portions thereof),etc.

FIG. 15 illustrates an example user interface screen 1500 that may beused in systems and methods in accordance with at least some examples ofthis invention. As shown in FIG. 15, the interface screen 1500 maypresent much information to the player, including information relatingto a specific game or practice session, as well as information relatingto more long term use of systems and methods in accordance with thisinvention. For example, as shown in FIG. 15, user interfaces 1500 inaccordance with this invention may provide information relating to theoverall total number of games played by the player, the total overallminutes logged by the player using the system, the player's top speedover that time period, and the player's top speed while in possession ofthe ball (e.g., while he was personally in possession of the ball orwithin close proximity to it, not while the team was in possession).

The interface screen 1500 also provides information for an individualgame (with the ability to select among the various stored games on thesystem). As illustrated in FIG. 15, in this example interface, thescreen 1500 displays information relating to the player's movement speedduring this specific game (i.e., Game 24), movement speed while inpossession of the ball during this specific game, the number of“sprints” during the game (e.g., the number of times that the player'smovement speed exceeded a predetermined threshold, such as 75% of theirtop speed), and the player's highest “kick power” during the course ofthe game (e.g., the highest ball speed logged from the player's kick).Also, if desired, the user interface could be adapted to allow userselection of various different metrics or information to be displayed.

The “Gameline” portion of this example interface screen 1500 includesinformation relating to the specific game displayed. For example, in theillustrated screen 1500, the Gameline includes information indicatingthe entire distance that the player moved during the game, the number ofminutes played, and the number of “touches” or times that the player had“possession” of the ball. Additionally, in this example, the Gamelineincludes information regarding the user's speed over the course of thegame, as well as the times that the player's team had possession of theball. In this example, the dark black portions 1502 a of the player'smovement velocity line 1502 indicate when the player's team did not havepossession of the ball and the lighter gray portions 1502 b of theplayer's movement velocity line 1502 indicate when the player's team hadpossession of the ball. The visible portion of the movement velocityline 1502 can be changed so that any desired portion of the game can bedisplayed (the 60 to 90 minute time period is displayed in thisillustrated example), or an entire game (or the portion in which theplayer played) can be displayed in a single view, if desired. Othermetrics may be displayed in the Gameline portion of the interface 1500,if desired, without departing from this invention, either in place ofthis movement velocity time line 1502 or in addition to it (such as thetimes when the player kicked the ball, the player's goals (as shown),the player's successful passes, the team's goals, etc.). Also, ifdesired, user interfaces according to the invention could be designed toallow user selection of various different metrics in the Gamelineportion.

User interfaces in accordance with at least some examples of thisinvention also may display team information (or even competitor teaminformation), if more than one player is equipped with the sensors anddetectors in accordance with this invention. FIG. 16 illustrates anexample user interface screen 1600 in which data from five players aredisplayed in a single screen. In this example, the player movementvelocity data (e.g., top sprint speed) for five players thatparticipated in a single game (Game 24) is displayed, e.g., so that theplayers or coaches can compare performance characteristics. Furthermore,in this example interface screen 1600, data for other games can beselected, or data for other measured metrics may be displayed in thisplural player comparative manner (e.g., speed on ball, number ofsprints, number of touches, kick power, number of successful passes,number of steals, number of turnovers, etc.). Other team data or othermeasured metrics also may be made available and displayed in this typeof user interface screen without departing from this invention.

Systems and methods in accordance with at least some examples of thisinvention may include “goals” or “challenges.” While the goals may beset by the individual player for himself or herself, optionally, thegoals or challenges may be set by a coach, a teammate, a competitor,etc. FIGS. 17A and 17B illustrate an example. FIG. 17A illustrates auser interface screen similar to that of FIG. 15, but in this example,each data metric further includes “grayed out” blocks that represent aplayer's “goal” or “challenge” for that metric. For example, in FIG.17A, the data from Game 24 is displayed with an indication of theplayer's performance in that game (the blackened in boxes) and anindication of where the player's performance stood with respect to their“goal” or “challenge” levels (the grayed out boxes). The specific metricfor the “goal” or “challenge” may be displayed in any desired manner,e.g., by clicking on the last box associated with the goal or challenge,by hovering over a grayed-out box, through a continuous display, etc.Notably, in this illustrated example, the system indicates that theplayer's overall top “speed” goal or challenge is 18.4 km/h, while inthe present game they had only run at a top speed of 17.2 km/h.

In the next game (Game 25), however, as illustrated in the userinterface screen 1750 of FIG. 17B, Player A achieved his or her speedgoal by running 18.5 km/h. In this instance, systems and methods inaccordance with at least some examples of this invention may provide acongratulatory message (e.g., textually, visually, audibly, etc., notethe changes in the Gameline portion of FIG. 17B as compared to FIG.17A). Furthermore, if desired, in an effort to keep the playermotivated, a new “goal” or “challenge” can be calculated and displayedfor the player. Also, if desired, when presented as a challenge from athird party, systems and methods in accordance with at least someexamples of this invention may send a message to the challenger (oroffer to let the player compose a message to his or her challenger) toadvise that the challenge had been met. Other “rewards,” motivationalinformation, or other interaction may be provided, if desired, withoutdeparting from this invention.

User interfaces for athletic performance monitoring systems and methodsin accordance with this invention may take on a wide variety of formsand formats and provide a variety of different types of displays andinformation without departing from this invention. FIG. 18 illustratesanother example user interface screen 1800 in which player speed,kicking power, and individual possession information is displayed on amore circular graph (as compared to the linear graphs of FIGS. 15-17B).FIG. 18 also shows a player possession time metric as opposed to thespeed on ball and number of sprint metrics provided in FIGS. 15, 17A,and 17B. Displays of other metrics or combinations of metrics arepossible without departing from this invention. Other graphical or otherdisplays of the desired metric information also may be provided withoutdeparting from this invention.

G. Throwing v. Kicking Determinations

In at least some example systems and methods according to thisinvention, it may be desirable to distinguish between situations inwhich a ball or piece of sporting equipment has been thrown and when ithas been kicked. This may be useful in various sports, such as soccer(e.g., to determine when play resumed and how it resumed, as will bedescribed in more detail below) and basketball (e.g., to determinewhether possession should be awarded to the other team). A determinationof throwing v. kicking also may be useful for determining other metrics,such as possession time in soccer, as the throwing v. kickingdetermination may be useful in helping to determine when a ball goes outof bounds (e.g., on the side) during a soccer game (e.g., time between athrowing action and a previously determined kicking action may beconsidered “out of bounds” time in soccer (as a throwing action often isused to restart play from an out of bounds condition), and that amountof time may be deducted from a team's determined ball possession time).Aspects of this metric also may be useful in basketball, for example, todetermine when the ball struck the ground (more like a “kicking action”sensor response, as described below) as opposed to being pushed with ahand (such as for a shot or pass).

In accordance with at least some examples of this invention, asillustrated in FIGS. 19A and 19B, output from one or more pressuresensors (e.g., a ball mounted pressure sensor and/or a foot mountedpressure sensor) and/or one or more accelerometers (or other inertialsensing device) (e.g., ball mounted and/or foot mounted) may be used fordetermining whether a ball has been thrown or kicked. FIG. 19Aillustrates the ball sensor responses during a typical throwing action(such as a throw-in in soccer, a shot in basketball, etc.) and FIG. 19Billustrates the ball sensor responses during a typical kicking action(or a dribble off the floor in basketball). As shown in FIG. 19A, theoutput from both a pressure sensor and an acceleration sensor during athrowing action will tend to be a slow, long signal (or, depending onthe throw, there may be little to no pressure signal at all from asimple throwing action). During a kicking action, however, asillustrated in FIG. 19B, a relatively short and strong impulse signal isgenerated by both the pressure sensor and the accelerometer sensorfollowed by a low-rate slowdown of the ball (e.g., due to aerodynamics,gravity, etc.). The pressure change inside the ball (or other object) ismuch slower when thrown as compared to when kicked, but the pressurechange may last a longer time during the course of a throw event.Additionally, the accelerometer output will tend to constitute a muchlonger signal and lower level of acceleration from a throw as comparedto a kick. These differences in sensor output between FIGS. 19A and 19Bwill allow systems and methods in accordance with examples of thisinvention to distinguish between throwing actions (such as throw-ins insoccer, shots or passes in basketball, etc.) and kicking actions (orother similar actions that will generate a similar pressure andaccelerometer output spike, such as ball contact with ground (e.g., adribble), ball contact with a basketball rim, ball or puck contact witha goalpost or hockey stick (e.g., in football, hockey, soccer, etc.)).

H. “Explosiveness” Determinations

FIG. 20 illustrates an example of features that may be involved indetermination of an “explosiveness” or “power” metric. Some metrics thatmay be useful in athletic performance monitoring systems and methodsaccording to at least some examples of this invention relate to ways ofdetermining how hard an individual is working over the course of a gameor practice session. FIG. 20 illustrates various features involved indetermining one example “explosiveness” metric. When athletes are in acrouch position (e.g., as shown in FIG. 20, such as sprinters, footballlinemen, backs, or other players, etc.), their effectiveness at thestart of the activity is often determined by how quickly they springinto action (e.g., get out of the starting blocks, get out in front ofrushing defensive players to make a block, etc.). As shown in FIG. 20,determination of the distance between the athlete's feet and his/herupper body or torso, and the rate of change of this distance, can beused to determine an “explosiveness” metric that may be a gauge of theathlete's performance. Note, for example, the differences in orientationand length between the foot based module and the torso based module fromthe crouch position (the solid line) and the initial “explosion”position (the broken line). Measuring and tracking the distance and/orangle and their rates of change may be used to determine variousfeatures or other metrics, like initial explosiveness, explosivenessover the course of a game or training sessions, improvements inexplosiveness, effectiveness of training or conditioning, etc.

This measurement system may utilize two sensors (e.g., wireless sensors)or other modules that allow determination of the relative distancebetween two points (e.g. a foot based point and a torso or body corebased point). The two sensors may report their positions to therebyallow their relative positions to be determined, and this informationmay be stored (e.g., in one of the sensors or modules, on anotherathlete carried device, such as a mobile phone, watch, PDA, audio/videoplayback device, MP3 player, etc.), transmitted to another location(such as a remote server, a laptop or other computer, etc.), etc.

Similar explosiveness or power metrics also could be used, for example,tied to a jumping action, such as a jumping action in basketball (orother sports).

FIG. 21 illustrates another potential manner of measuring explosivenessor power metrics by determining the player's acceleration. Generally, asillustrated in FIG. 21, when accelerating (as shown toward the left ofFIG. 21), an athlete's center of mass and/or torso are generally locatedahead of his/her feet. When a steady state pace is achieved (or whenslowing down, as shown more toward the right of FIG. 21), the center ofmass and/or torso more closely align vertically. In this example metric,the changing angle of the player's torso is determined, and the rate ofchange of this angle will provide information as to whether the athleteis accelerating, moving at a steady state pace, or decelerating.

As some more specific examples of the system of FIG. 21, the sensingsystem may include one or more of: an accelerometer, a gyroscope, orother rotation sensing devices. A sensor may be placed on the upper bodyand used to measure the rate of change of the angle of the upper bodywith respect to the body center (e.g., waist or pelvic area) and/or thefeet. As another example, if desired, the rate of change of the gravityvector may be measured by an upper body mounted accelerometer.Optionally, if desired, this metric may be used in combination with footor leg movement metrics to provide additional information or moredetailed metrics with respect to specific activities. The foot or legmovement metric(s) may be measured using an accelerometer, apiezoelectric sensor, etc., to measure foot movement speed, foot impactforce, foot loft time, etc. Combining the rate of torso angle changewith other data, such as one or more of: body weight, height, footlocation, foot movement, foot speed, or the like, may allow actualplayer acceleration to be determined.

I. Additional Potential Features and/or Metrics that May be Measured inSystems and Methods According to this Invention

As noted above, while much of the above description has been provided interms of use in a soccer environment, given the benefit of thisdisclosure, one skilled in the art could readily extend aspects andfeatures of this invention to other team sports, such as basketball,American football, hockey, rugby, field hockey, lacrosse, baseball,cricket, volleyball, badminton, tennis, and the like. Different metricsmay be tracked, stored, and/or displayed for different players or fordifferent positions on the team (e.g., goalie versus center versusdefensemen, etc.).

A wide variety of parameters or metrics may be measured and determinedwithout departing from this invention. Including the various metricsdescribed above, additional metrics that may be measured in systems andmethods in accordance with at least some examples of this invention mayinclude: vertical leap (e.g., with a body core mounted three axisaccelerometer); number of leaps; jump height with the ball; jump heightwithout the ball; team pace or match pace (an aggregate measure ofspeed, distance, and/or other data from all players on the team);on-field position and/or movement; on-field position and/or movementwith respect to the ball's location; average speed intervals (on and offball); top speed intervals (on and off ball); total distance moved (onand off ball); distance intervals; shot power; shots on goal; assists;blocks; saves; game duration; playing time; typical game statistics;etc. Data relating to any of these or the other metrics above may becombined and/or further processed, if desired, to provide other metricsor indices relating to the athlete's performance, such as a “hustle” or“intensity index,” the number of shots without a goal, average number ofshots between goals, tackles per game, minutes without giving up a goal,shot blocks, etc.

Another useful metric similar to one described above also may be termed“explosiveness,” e.g., data and metrics tracking the player's initialmovements from a slowed pace or stopped position. For example, thismetric may include acceleration information relating to the first two orthree steps. Additionally or alternatively, this metric may includeinformation relating to the force applied to the athlete's foot or feeteven before the athlete moves (i.e., as he or she prepares or “loads up”to take off).

Another useful metric may involve consideration of the differences in aplayer's performance over the course of a single game. If a player has adramatic drop off later in the game, this information could be useful tothe coach (e.g., to provide motivation, to induce substitution, etc.) orto the player (e.g., to induce work on conditioning, etc.).

Systems and methods according to this invention also may allow userinput of other information relative to the game, such as temperature,humidity, wind conditions, field conditions (e.g., wet, dry, etc.), etc.Tracking these features may be useful to see how players perform under avariety of conditions and determining which players to field under agiven set of conditions.

If desired, aspects of this invention also may include various automaticON/OFF switching features, e.g., to preserve battery power for theactual game time but to assure that the desired data is captured. As oneexample, a referee, scorer, or coach could include a device that turnsall devices ON and OFF from a central location. As another example, ifdesired, detection of the referee's whistle frequency could be used toturn the devices on and off.

Systems and methods according to examples of this invention also mayallow an individual to compare his or her performance (e.g., anymeasured metric) to that of a professional athlete or another player(e.g., on a game-per-game level, on a metric level, etc.). Trainingadvice or practice drills also could be downloaded to or provided to theplayer by systems and methods in accordance with this invention,optionally, based on the measured performance metrics stored in thesystem. Additionally, if desired, systems and methods according toexamples of this invention also may be used to recreate an animation ofthe game (and the player's performance) on the computer screen after thegame has been completed (or even while it is going on).

Aspects of this invention also may be useful for other purposes withinthe context of a team sport, such as a referee assistant (e.g., did aplayer have possession, was a player out of bounds, was the ball out ofbounds, was the shot made before time expired, etc.). Coaches also coulduse features of the invention during practices, drills, or even duringthe overall game to determine which players should play, which playersshould play together, which players should not play together, as amotivational tool, when to substitute, etc.

The following description, in conjunction with FIGS. 22 through 94,provides some detailed information relating to measurement of variousmetrics and various other features of systems and methods according toexamples of this invention that may be useful in various environments,including for use in monitoring athletic performance in the context ofsoccer (e.g., for use in a soccer game, soccer training, soccerpractice, etc.) or other team based sports. FIGS. 22 through 94illustrate various soccer (or other sport) scenarios (e.g., typical gameor practice events, types of plays, types of ball control or ballpossession transfer, etc.) as well example “sensing architecture” andexample sensors and/or combinations of sensors (called “PotentialEmbodiments” in FIGS. 22-94) that may be useful in collecting the dataand making the measurements for determining features, aspects, andmetrics based on that scenario. The following abbreviations are includedin the various figures, and these abbreviations have the meaningsprovided below:

Motion Sensing Definitions:

-   -   CS—Core mass sensor (sensor(s) on the athlete's body core        capturing player motion data)    -   SS—Shoe (or foot) based sensor (sensor(s) in one or more shoes        to capture foot motion data)    -   BS—Ball Sensor (sensor(s) in the ball to capture ball motion        data)

Proximity Sensing Definitions:

-   -   CP—Core mass proximity sensor (sensor(s) on the athlete's body        creating a proximity sensing field around the player, e.g., as        described above)    -   FP—Foot based proximity sensor (sensor(s) mounted on the shoes        or near the foot creating a tight proximity sensing region        between the ball and a foot (which may be the same as or similar        to the core mass sensors described above))    -   IM—Impact sensor (a time stamped impact on a foot sensor and a        ball sensor indicating foot/ball contact)

Sensor Types:

-   -   R—Radar based sensor system    -   RF—Radio (or radio frequency) based sensor system    -   GPS—Global positioning satellite based sensor system    -   M—Magnet based sensor system (e.g., Hall Effect sensors, etc.)    -   MC—Magnetic coil based sensor system    -   P—Pressure sensor system (e.g., piezoelectrics, etc.)    -   A—Accelerometer sensor system    -   G—Gyroscope based sensor system    -   T—Time sensor or clock    -   C—Compass (e.g., electronic compass)

FIGS. 22 through 35 illustrate various potential features for detectinginteractions of soccer players with respect to the ball, e.g., during agame, practice session, etc. The features of these “player on ball”determination systems, methods, and metrics will be described in moredetail below.

FIG. 22—Receive Possession:

To create useful metrics for the game of soccer, systems and methodsaccording to at least some examples of this invention will have at leastsome manner of determining when possession of the ball starts (e.g., todetermine individual player possession time, team possession time,etc.). Therefore, systems and methods according to examples of thisinvention include some manner of choosing and determining events thatstart the possession clock and/or keep the possession clock running. Inaccordance with this example of the invention, sensors in the shoe andthe ball may be used to determine and start a possession event.Proximity sensing alone (e.g., player proximity to the ball, asdescribed above) may not be sufficient to determine accurately when apossession actually starts for all uses, so additional sensing methodsmay be provided to more accurately determine when a possession timeclock can be initiated in accordance with at least some examples of thisinvention.

As shown in FIG. 22, in this example system and method according to theinvention, a sensing system in the ball (pressure sensor, accelerometer,gyro, magnetometer, etc.) detects an impact to the ball, andcoincidently a sensor (accelerometer, piezo element, or other inertialsensing system) in the boot of a player matches the impact time exactly.This precise moment may be used in at least some systems and methodsaccording to this invention to determine the start of possession. Inother words, as illustrated in FIG. 22, when Player A kicks the balltoward Player B, Player B's proximity to the ball and then contactbetween Player B's shoe and the ball, optionally along with departure ofthe ball from the proximity of Player A, will be used to establishpossession and start a possession time clock for Player B and/orcontinue a team possession time clock for one team (if Player A andPlayer B are on the same team) and/or start a new team possession timeclock (if Player A and Player B are on different teams). Variousexamples of the sensing architecture and sensor systems that may be usedfor determining this metric are illustrated in FIG. 22.

FIG. 23—Player Possession:

In addition to determining when an individual player's possessionstarts, systems and methods according to at least some examples of thisinvention further may wish to track how long an individual playermaintains possession of the ball. FIG. 23 illustrates various examplefeatures of potential systems and methods for determining individualplayer possession. This example system and method according to theinvention uses sensors in the shoe and the ball to start this event (asdescribed above in conjunction with FIG. 22), and then uses proximitydetection features to confirm that the player has kept possession afterthat initial contact and the length of time associated with thispossession. For example, when the player kicks the ball out of theirproximity (at least under certain conditions as will be described inmore detail below) or if the player is tackled and loses possession (aswill be described in more detail below), these events may be determinedas possession ending events (which can be used to at least temporarilystop that player's possession time clock). Various examples ofdetermining player possession and/or proximity may be used, as describedabove.

As some more specific examples, as noted above, a sensing system in theball (e.g., pressure sensor, accelerometer, gyro, magnetometer, etc.)detects an impact to the ball, and coincidently a sensor in the boot ofa player (e.g., accelerometer, piezo element, or other inertial sensingsystem) matches the impact time exactly. This precise moment determinesthe start of possession. Then, an on body proximity sensor can be used(e.g., as described above, such as a RADAR, radio frequency, or magnetsystem) to confirm that the ball remains in the field of proximity and(via the time counting sensor) the amount of time that the ball remainswithin this field of proximity (optionally, without another playerhaving contact with the ball, which would constitute a change inindividual possession (but not necessarily team possession)).

FIG. 24—Speed on Ball:

As described above, one metric that may be particularly useful fordetermination by systems and methods in accordance with examples of thisinvention constitutes a player's “speed on ball” metric (e.g., a measureof how fast a player moves while in possession of the ball). FIG. 24illustrates an example system and method. In this example system andmethod, a proximity sensing system (such as RADAR, radio frequency,magnetic sensors, etc.) is used to determine when the ball is inproximity to the player. Impact sensing systems in the boot(accelerometer, piezo element, etc.) are matched to impact sensingsystems in the ball (pressure sensor, accelerometer, gyro, etc.) todetermine when the foot impacts the ball. Speed on ball is thendetermined as the speed at which the player moves while in continuousproximity to the ball, with repeated foot impacts to the ball, and/or asthe speed at which the player moves while the ball is determined tocontinuously be in his/her possession.

As another alternative, systems and methods according to at least someexamples of this invention may continue the “speed on ball” measurementmetric (as well as a player possession metric as described above) evenwhen the ball falls outside the core proximity sensing capabilitiesunder certain circumstances. For example, the speed and ball and/orplayer possession metrics may continue running their clocks when theball moves outside the core proximity sensing capabilities as long as:(a) the ball never is detected to be in the proximity of another playerand/or (b) the amount of time the ball is outside the player's coreproximity sensing range is below a specified time threshold. This wouldcover situations where a player is running fast and making long dribbles(which may extend outside the core proximity detection range) whilestill consistently maintaining control of the ball.

FIG. 25—Short, Break, and Long Dribbles:

As described above, output from an impact sensing system inside the ball(e.g., accelerometer, pressure sensor, etc.) may match timing withoutput from an impact sensing system inside the boot to time-matchimpacts so that systems and methods according to at least some examplesof this invention will be able to determine when the ball is struck by aspecific foot. A proximity sensing system also may be employed (e.g.,magnetic sensing, RSSI, etc.) to determine when the ball is in proximityto the specific players on the field. A “dribble” action may bedetermined, e.g., by repeated foot/ball contacts by a single player.Combining a dribble action determination with other metrics, such asplayer speed/acceleration metrics, can provide other useful informationfor evaluating athletic performance. More specifically, systems andmethods according to at least some examples of this invention candifferentiate between different types of dribbles and allowdetermination of different metrics.

As some more specific examples, the following dribble types may bedetermined: (a) a “short dribble” can be defined as player dribbling theball with a low player speed (e.g., below a threshold speed, optionallya threshold speed based on the individual player's top sprinting speedand/or average running speed), (b) a “break dribble” (or “break away”dribbling) can be defined as a player with an accelerating player speed,and (c) a “long dribble” can be defined as a player dribbling beginningwith a break dribble followed by a steady player velocity and/or thenrepeated foot contact by the same player. Systems and methods accordingto aspects of this invention may further break up player possession timeinto the various times that the player spent in these various differentdribbling activities.

FIG. 26—Knock on and Sprint:

This common play in the game of soccer may be detected by systems andmethods according to at least some examples of this invention using amultitude of sensing systems and combining their outputs. An impactsensing system inside the ball (e.g., accelerometer, pressure sensor,etc.) is matched to an impact sensing system inside the boot totime-match impacts to know when the ball is struck by a specific foot,as described above. Additionally, a player speed sensing system (e.g.,foot based, core-mounted inertial sensing based, etc.) may be used todetermine player speed. Using a determination of the start of possessionas described above, one example sequence of events that could lead to adetermination of a “knock on and sprint” event may include the followingsequential steps:

-   -   a. Ball impact is detected along with a foot impact, determining        start of possession;    -   b. The proximity sensing system determines when an opposing        player comes within the possession radius;    -   c. The ball and shoe sensors then determine a kick by the player        having possession;    -   d. The speed sensing system detects a sprint while the ball is        located outside the proximity detection radius from the player;    -   e. The same player then runs onto the ball, and the proximity        sensing system determines player/ball proximity;    -   f. Then, the start of possession determination methods described        above are then used to determine the resumption of the player's        possession.        The number of “knock on and sprint” events detected for an        individual player during the course of a game (or other time        period) may be determined as a metric, e.g., as a measure of the        player's effectiveness at avoiding defensemen, as a player's        ball control capability, etc.

FIG. 27—Close Control:

One important skill in the game of soccer is the ability of a player tokeep the ball within very close proximity to himself or herself whilestill reaching very high running speeds. Systems and methods accordingto at least some examples of this invention may be used to determine aplayer's top speed (or average speed, etc.) when keeping the ball inclose proximity. As some more specific examples, an inertial sensingsystem may be employed to determine player speed and movement distance(e.g., accelerometers, piezo elements, etc.), and an impact sensingsystem inside the ball (e.g., accelerometer, pressure sensor, etc.) maybe matched to an inertial sensing system inside the boot to time-matchimpacts to enable determination of when the ball is struck by a specificfoot. Optionally, sensor systems may be provided to enable determinationof the path that the foot has traveled over the course of its movement(e.g., accelerometers, gyros, etc.). A proximity sensing system also isemployed (e.g., magnetic sensing, radio frequency, RADAR, etc.) toenable determinations of when the ball is in proximity to the players onthe field. Using such hardware, determination of “close control” may beperformed as follows:

-   -   a. The proximity detection systems determine when the ball is        close in to the player.    -   b. Speed is determined using an on-body or on shoe speed and/or        distance system, such as an accelerometer, piezo element, or        similar.    -   c. At no time during the run can the ball leave a defined        proximity from the player.    -   Such a system may enable determination of the player's top        speed, average speed, and/or other speed characteristics while        at all times maintaining the ball within a defined proximity or        distance from his/her body (i.e., movement speed while        maintaining close control over the ball). Such a metric may be        useful in identifying players with breakaway speed that will        still have a good ability to maintain control and possession of        the ball even at high speeds.

FIG. 28—Dribble Foot Distribution:

This example aspect of the invention combines an impact sensing systemin each of the user's shoes and an impact detection system in the ball,as has been described above. Time correlated impact events between theball and each individual shoe may be ascertained to enable determinationof which foot struck the ball. This data can be logged over the courseof a game (or any desired time period), and the system can store thisinformation and/or wirelessly communicate the data to a remote location.The data can be presented to the player (or coach, etc.), e.g., as achart, graph, histogram, etc., to inform the player how often they useeach foot during dribbling. This metric also can be used at least inpart to formulate a report for the athlete that includes suggestions onhow to improve. This metric allows determination of the dominant footused by the athlete, which can lead to further metrics (such asdevelopment of weak foot to provide better shots on goal, etc).

FIG. 29—Control of Incoming Ball:

This example aspect of the invention uses a combination of varioussensing systems described above to create a skill metric describing howwell a player deals with an incoming ball (e.g., from a pass, during asteal, etc.). A formula can be created by the combination of two or moreof the following metrics, some of which are described above and some ofwhich are described in more detail below): (a) Kick Style, (b) Speed ofthe Ball, (c) Proximity, (d) Deceleration of the Ball (as determined byinertial/pressure sensing systems in the ball), and/or (e) Player Speed.As a more specific example, if desired, a ratio of (Speed of theIncoming Ball+Player Speed)/Ball Proximity after first touch may providea useful metric. If the ball is maintained in close proximity to theplayer during an incoming kick, this indicates good player control overthe ball. Maintaining close proximity to the incoming ball after theplayer's first touch, particularly when the ball is moving at high speedand/or the player is moving at high speed, is even more difficult.Therefore, a high ratio as described above would provide one potentialincoming ball control metric. Other control metrics may be determined,e.g., using the other metrics described above without departing fromthis invention.

FIG. 30—One Touch Pass:

A “one touch pass” is a frequently used play in soccer that can be veryinfluential in the game, allowing for fast movement of the ball andcreation of space between the ball and defensemen. A “one touch pass”determination may be accomplished in a manner similar to a combinationof a “pass” determination and a “possession” determination as describedabove. In the “one touch pass” scenario, the ball comes into theplayer's proximity rapidly, strikes one of the player's feet one time(e.g., determined using time matched ball and boot impact sensors),travels out of proximity, and (optionally), into possession or proximityof a teammate. While the player making the one touch pass may not(and/or need not) get possession time credit (because his/her possessiontime is too short), counting the player's involvement in the play and/orcounting the player's pass can be very valuable information and a veryvaluable metric (e.g., for determining various other data or metrics,such as assists, passing efficiency, etc.) in understanding theeffectiveness of a particular player.

FIG. 31—Tackle Avoided:

For determination of this event and/or metric, output from an impactsensing system inside the ball is time matched with output from animpact sensing system inside the boot to enable a determination of whenthe ball is struck by a specific foot. A proximity sensing system alsomay be employed, as described above, to enable a determination of whenthe ball is in proximity to the various players on the field. Adetermination of a “tackle avoided” metric according to this example ofthe invention uses the above defined dribble metric and a contested timedetermination (e.g., defined as a time period when the ball is locatedwithin close proximity to players on both teams). The following sensoroutputs may be utilized to determine whether a tackle has been avoided:

-   -   a. A dribble or possession is recorded by or awarded to a        particular player.    -   b. The ball proximity sensing system detects a “contested time”        event when two or more players, with at least one from each of        the teams on the pitch, located within a predetermined proximity        to the ball.    -   c. A short time later, another dribble or possession        determination is recorded by or awarded to the same player as in        step a above, but with no other players in proximity to the ball        (as detected by the proximity sensing system).        This sequence of events may be used to award a “tackle avoided”        event to the player maintaining possession. Tabulation of such        events may provide useful ball control metrics for the various        players.

FIG. 32—Tackle Successful:

Determination of successful tackles also is a useful metric that may betracked by systems and methods according to at least some examples ofthis invention. Determination of this metric is substantially the sameas determination of the “Tackle Avoided” metric described above, exceptto have a successful tackle determination, an opposition player who wasin proximity to the ball, a player that went in for the tackle, leavesin possession of the ball or successfully passes the ball to a teammate(a player on the opposite team from the player initially awardedpossession). More specifically, as shown in FIG. 32, while Player A haspossession of the ball (e.g., is dribbling), Player B from the opposingteam moves in to attempt a tackle; Player A loses possession to Player Bduring the contested possession time; and Player B leaves with solepossession of the ball or passes the ball to a team member. Tabulationof successful tackle events may provide useful ball control metrics forthe various players, e.g., for determining poor ball handlers, superiordefensive players, etc.

FIG. 33—A “Skin” Event:

Determination of a “skin” event may utilize an impact sensing systeminside the ball and impact sensing systems inside the boots to enabletime-matching of ball and boot impacts and to enable determination ofwhen the ball is struck by a specific foot. This determination also mayutilize a proximity sensing system to enable a determination of when theball is in proximity to the various players on the field, and, in atleast some examples, a core-mounted player rotational sensor (e.g., acompass sensor, a gyro sensor, an accelerometer, etc.) to enable adetermination of which direction the player is facing and/or playerrelative rotational information. Using such a system, a “skin” may bedefined by the following sequence of events:

-   -   a. A first player receives a pass by registering proximity of        the ball to the player as well as a simultaneous impact event on        both the ball and boot.    -   b. A second player is detected by the ball proximity sensing        system (e.g., beginning a contested time period determination).    -   c. The core mounted rotational sensor registers a 360 degree        rotation of the first player (or some other significant        rotational or other directional change move).    -   d. The proximity sensing system from the ball senses only the        first player in proximity of the ball (e.g., a break away from        the second player plus possession of or proximity to the ball).    -   e. A dribble or pass event is then recorded by the first player.

FIG. 34—Possession “Heat Map”:

Using the possession and/or player proximity to the ball determinationtechnology described above also can provide useful information forpresentation of the data for player or coach review. For example,computer display screens and interfaces in accordance with at least someexample of this invention can provide a graphic visualization of theamount of time each player was near the ball and involved in the game.For example, as illustrated in FIG. 34, a first region in immediatevicinity of a visual depiction of the player (e.g., a photo, an avatar,etc.), optionally having a first color or a first color intensity, mayindicate the amount of time the player had possession of the ball; asecond region surrounding the first region (optionally having a secondcolor or a lighter color intensity from that described above) mayindicate the amount of time that the player was in proximity to the ballwhether or not in possession (e.g., contested time, defending time,etc.); and, optionally, a third region surrounding the first and secondregions that indicates the entire game time or the entire time that thespecifically identified player was on the pitch and in the game. Suchdata presentation can provide a quick visual indicator (optionallycoupled with other data on the display, such as total play time,percentages, etc.) for the player or coach as to a specific player'sinvolvement in the game.

FIG. 35—Intensity:

An intensity metric can be created, for example, using one or more ofthe sensing systems described above (e.g., player to ball proximitysensing, player to player proximity sensing, player speed, passes,tackles, etc.). As some more specific examples, an intensity metric mayinclude information such as involvement in a play (e.g., ball proximityinformation (number of times close to the ball, number of times inpossession of the ball, etc.), number of passes (including one touchpasses), etc.), player proximity information (number of times close toanother player, number of successful tackles, etc.), speed of the playeron ball, speed of the player off ball, time spent near oppositionplayers that are on ball, man-to-man marking, closing in on the ball,tracking back, etc. This information also can be displayed on a computerdisplay device and/or a user interface therefore, in any desired manner,e.g., as shown in FIG. 35.

FIGS. 36 through 45 illustrate various potential features for detectingand/or measuring various metrics relating to soccer players' kickingactions, e.g., during a game, practice session, etc. The features ofthese “kick” feature determination systems, methods, and metrics will bedescribed in more detail below.

FIG. 36—Kick Zone Determinations:

At least some systems and methods according to examples of thisinvention will be able to determine the area of the boot and/or footthat impacts the ball during a kick. Such systems and methods may use,for example, an impact vector reporting sensor system (such as a 3-axisaccelerometer) in the boot, combined with sensing mechanisms in the ballthat can communicate the exact times of impacts. The acceleration vectorproduced by the impact of the boot with the ball is matched up to theexact time in which the ball is impacted. Because the soccer ball isapproximately spherical, the impact vector as reported by the boot willbe normal to the surface of the boot that impacted the ball. Therefore adistribution of kick zones on the surface of the boot can be output tothe user to help inform skill level and areas of development.

This kick zone distribution information may be displayed on computerdisplays and/or user interfaces in accordance with at least someexamples of this invention, for example, as shown in FIG. 36, where thecolor intensity or color area corresponds to the number of kicksproduced in that area of the shoe (e.g., 1-5 kicks in a zone makes thezone appear red, 6-10 kicks in a zone makes the zone appear blue, etc.).Any number of zones may be provided in the display or a point for eachindividual kick may be provided in the display without departing fromthis invention (optionally with the ability for the user to “drill down”to get more data about the individual kick, such as ball speed, traveldistance, kick results (e.g., successful pass, goal, turnover, out ofbounds, etc.), and the like).

As an alternative, a rotational sensing system may be provided at ornear the center of the shoe, and this sensing system can be used todetermine the immediate rotation of the foot that occurs when the ballis impacted. This information will allow systems and methods accordingto this example of the invention to determine if the ball impact occursahead or behind the center of rotation axis of the sensor, as well asthe side of the foot that impacts the ball.

FIG. 37—Ball Flight Path Distribution:

As another potential feature, systems and methods according to at leastsome examples of this invention will allow for determination of a ballflight path distribution. In this example system and method, the outputof a three-dimensional accelerometer in the ball is used in combinationwith the kick zone determination features described above. As a morespecific example, if the acceleration vector from the ball is known (andtherefore, the flight direction can be determined), this informationcombined with the impact location on the boot, allows the flight path ofthe ball to be determined. This information can then be fed into asystem that aggregates the distribution of these flight paths, and theinformation can be displayed on computer displays and/or user interfacesin accordance with at least some examples of this invention, forexample, as shown in FIG. 37, wherein the flight direction off the bootfrom one or more kicks over the course of a game or other time periodcan be displayed. The length of the lines shown in the display of FIG.37 may correlate to the length of the flight path of the ball(optionally with more data available for each individual kick, ifdesired, e.g., as described above). This information can be used byplayers and/or their coaches to determine appropriate drills or trainingsessions to help the player develop specific skills or improve his playand/or versatility. As shown in FIG. 37, the ball flight pathinformation may be combined with the kick zone information in thedisplay.

As some alternatives, a compass, gyro, or other rotational sensor can beadded to the system to more accurately determine flight path. Fasterrotations of the ball may be considered as producing a more curvedflight path due to the aerodynamics of the ball. In such systems andmethods, the ball flight path on the display of FIG. 37 may be displayedas a curved path with the degree of the curve displayed correlating tothe amount of spin and direction of spin applied to the ball during thekick.

FIG. 38—Longest in-Game Kick:

As another metric, systems and methods in accordance with at least someexamples of this invention may determine the longest ball kick by anindividual player over the course of a game. As a more specific example,systems and methods according to at least some examples of thisinvention may use ball speed information (e.g., using known andcommercially available technology, such as systems and methods availablefrom CAIROS). Furthermore, this example system and method will collectdata using in-ball sensing capabilities (e.g., including, but notlimited to: pressure sensors, accelerometers, or gyros) to determine thefirst impact that occurs after the ball is kicked. Data relating to thekick speed combined with flight time data is then multiplied to get a“longest kick” metric. Additionally, if desired, ball travel directionalvector information (e.g., from in-ball sensing systems), such as kickelevational angle as discussed below, can be used to provide an initialball flight direction vector to provide further directional and distanceinformation. Those skilled in the art can add modifiers to the productof kick speed and flight time (e.g., rotational information) that takeinto account aerodynamic or other flight effects which may reduce thetotal flight distance.

FIG. 39—Kick Elevation Angle:

Kick elevation angle may be an important metric in the game of soccer,particularly when it comes to game events, such as free kicks andpenalty kicks. For example, on a penalty kick, a ball flight having toohigh of an elevational angle combined with high speed will never becapable of scoring a goal (e.g., if the ball sails over the level of thenet). Systems and methods according to at least some examples of thisinvention may determine the kick elevation angle by using one ofmultiple methods of determining the gravity vector (e.g., such as anaccelerometer), and then combining it with kick vector data as reportedby an inertial sensing system within the soccer ball. The elevationangle of the kick with respect to gravity then may be determined andreported by the ball to a remote system (or stored for later download oruse).

FIG. 40—Kick-Type Distribution:

Systems and methods according to at least some examples of thisinvention further may determine the various types of kicks and a kicktype distribution for individual players (and/or for a team, a specificlineup or combination of players, etc.). Such systems and methods mayinclude use of an impact sensing system inside the ball (e.g.,accelerometer, pressure sensor, etc.) which may be matched to aninertial sensing system inside the boot to time-match impacts, whichallows determination of when the ball is struck by a specific foot. Theboot further may include sensors that allow determination of the paththat the foot has traveled over the course of the kick (e.g., gyro,accelerometer, etc.). A proximity sensing system also may be employed(e.g., magnetic sensing, RSSI, etc.) to allow determination of when theball is in proximity to the players on the field. A core-mounted playerrotational sensor also may be employed (e.g., compass sensor, gyro,etc.) to understand which direction the player is facing as well asrelative rotational information, and an inertial sensing system on theplayer can be used to provide additional data. Detection ordetermination of kick-type distribution information may be accomplished,for example, in the following way:

-   -   a. Inertial sensors in the shoe detect the plant foot's impact        to the ground and static nature.    -   b. Core mounted rotational sensor wirelessly communicates the        core facing direction (e.g., to a remote location), or this data        is stored.    -   c. Inertial sensors in the kicking foot detect the path/arc that        the foot goes through during the kick.    -   d. The boot impact location is detected, e.g., using the systems        and/or methods described above.    -   e. The ball spin rate and velocity are then recorded and/or        broadcast by the ball via wireless communication (or this data        is stored).    -   f. All reported information is compiled to understand the total        kick type, and all kicks are then aggregated to create a        histogram (or similar graphical or tabular data or information)        showing the number of specific kick types (e.g., a left-to-right        curving kick, a straight kick, a right-to-left curving kick, the        degree of curvature, high trajectory kicks, low trajectory        kicks, kick speed, kick distance, etc.).        This data may be used to produce a graphical display        illustrating the projected ball trajectory and/or distribution        of kick types on a computer display.

As another alternative, if desired, this kick type distributioninformation may be combined with player-to-ball proximity sensingsystems and methods described above to determine when a kicked ballreaches a teammate. This data can be used to produce various passmetrics, such as a pass distribution metric (e.g., number of passes tovarious teammates, types of passes to teammates, etc.).

FIG. 41—Leg Power:

Systems and methods according to this example aspect of the inventionuse sensing systems to correlate ball speed and/or other ball flightcharacteristics to the path traveled by the foot before striking theball. By determining the amount of “backswing” of the foot, it can bedetermined how much power the athlete is able to put into the ball givena specific backswing.

As some more specific examples of making this leg power determination,an impact sensing system inside the ball (e.g., accelerometer, pressuresensor, etc.) is matched to an inertial sensing system inside the bootto time-match impacts to enable determination of when the ball is struckby a specific foot, as well as to sense the path that the foot hastraveled. A “leg power” metric may be determined in the following way:

-   -   a. An inertial sensing system inside the boot detects the        distance/amount of travel the foot moves in the backward        direction. Optionally, the inertial sensing system can detect        when the moment the foot stops during the backswing and begins        to move forward and then detects the amount of forward movement        the foot travels before striking the ball.    -   b. At the time of impact, the ball and shoe sensors        simultaneously record an impact, and that information is shared        via wireless communication (or stored).    -   c. Pressure and accelerometers inside the ball report the speed        of the ball immediately after the kick. Optionally an inertial        sensor inside the ball could record speed.    -   d. Ball speed and foot travel path can then be correlated to        determine how far the boot traveled before striking the ball.    -   e. Leg power is inversely proportional to the amount of distance        the foot covered before the ball was struck, and is directly        proportional to the speed of the ball immediately after impact.        As another option, the peak pressure inside the ball can be used        instead of the true ball speed, as the peak pressure will        correlate to ball speed. As another option, the magnitude of        acceleration of the ball immediately after kick may be used as        opposed to the ball speed because these values will correlate to        one another as well.        The leg power metric can provide useful data for a player or        coach, e.g., to identify stronger players, to identify areas of        individuals needing work or training, to compare one leg's        capabilities and use against the other leg, etc.

FIG. 42—Kick/Pass Style:

This example aspect of the invention provides a sensing system that candetermine the type of kick that was made on a soccer ball. As one morespecific example, this example aspect of the invention allows the systemto differentiate between a lofted ball flight v. a ball flight that iscloser to or along the ground.

Output from an impact sensing system inside the ball (e.g.,accelerometer, pressure sensor, etc.) is matched to a rotational sensingsystem also provided with the ball (e.g., a compass sensor, gyro, etc.),and a lofted kick may be differentiated from an on-the-ground (or closerto the ground) kick, for example, by the following steps:

-   -   1. The impact sensing system in the ball senses an impact        simultaneously to sensing of an impact by the inertial sensing        system in the boot, thereby identifying that the ball has been        kicked.    -   2. Inertial and rotational sensors in the ball then sense        whether the ball is in free flight, e.g., defined by the rate at        which the ball is slowing down and/or losing altitude.        Additionally, rotational sensors sense a consistent rate of        rotation (or a relatively consistent rate of rotation)        indicating the ball is in the air.    -   3. If inertial and/or rotational sensors sense a dramatic        reduction in speed due to friction or interaction with the        ground, or a rapidly changing rate of rotation the ball, these        features can indicate that the ball is rolling on the ground.        Different kick types may be advantageous at different times        and/or under different circumstances in the game. This metric        can allow determination of these different kick types, which        also allows determination of the player's effectiveness at using        these different kick types (e.g., by determining which kick        types or the percentage of specific kick types that resulted in        a successful pass to a teammate or that scored a successful        goal, etc.).

FIG. 43—Kick Power at Speed:

Determination of this metric may use various data and metrics describedabove in this application. For example, using an on-body or in-shoesensing system (such as a three-dimensional accelerometer or apiezoelectric sensor element) to determine player speed, as well asproximity/possession technology described above, systems and methodsaccording to at least some examples of this invention further maydetermine the ability of a player to put significant impact force intokicking the ball while running at speed (a “kick power at speed”metric). The ball sensor(s) and the body-worn sensor(s) communicatetheir respective status, and this data then may be recorded on either ofthe two devices (or transmitted to an external device) for futurevisualization. This metric can be used as a skill metric to determinehow much ball control a player has while at their top speed. As somemore specific examples, any kick made while travelling at 75% of theplayer's top recorded running speed or higher (e.g., that particulargame's top running speed, or an overall top running speed in all of theplayer's collected data), optionally traveling at 75% of the player'stop recorded “on-ball” running speed or higher, may be a candidate fordetermining the kick power “at speed” metric so that high kick powersgenerated at relatively low speeds are not considered for inclusion inthis metric.

If desired, this information may be displayed or visualized on a webpage or hand-held device (such as a mobile phone) and compared withother metrics gathered by the system in previous and future games.

As an alternative, some ball speed sensing technology only has theability to determine a relative change in velocity. For example, if theball is already moving at 10 m/s and it is kicked such that the ballaccelerates to 50 m/s, limitations of this technology force it to reportonly a 40 m/s data value. In such a situation, the “kick power at speedmetric” may be determined using an on-body (or on-shoe) speed measuringsystem to wirelessly communicate with the ball sensor system, which canthen modify the reported ball speed value based on the speed of theplayer, thereby turning the measured value from a relative metric intoan absolute ball speed metric, which may have been determined to be“on-ball speed” using technology described above.

FIG. 44—Pass Accuracy at Speed:

This example aspect of systems and methods according to the inventionmeasures the metric of pass accuracy (e.g., successful passes toteammates) with the additional passing player's speed associated withit. Using an on-body or in-shoe sensing system (such as athree-dimensional accelerometer or a piezoelectric element) to determineplayer speed, as well as player-to-ball proximity/possession technologydescribed above, systems and methods according to at least some examplesof this invention can measure the ability of a player to accurately passto a teammate while moving at higher running speeds speed. More specificexamples of measuring this metric follow.

Via wireless communication methods, the ball sensor and body-wornsensors communicate their respective status (e.g., player making thekick, the player receiving possession after the kick, the speed of theplayer making the kick, etc.) which is then recorded on either of thetwo devices (or transmitted to an external device) for futurevisualization and review. This metric can be used as a skill metric todetermine how much ball control a player has while running at or neartheir top speed (e.g., while travelling at 75% of the player's toprecorded running speed or higher (e.g., that particular game's toprunning speed, or an overall top running speed in all of the player'scollected data), optionally while traveling at 75% of the player's toprecorded “on-ball” running speed or higher, etc.).

If desired, this information may be displayed or visualized on a webpage or hand-held device (such as a mobile phone) and compared withother metrics gathered by the system in previous and future games.

FIG. 45—Volley:

This example aspect of the invention measures information regardingvolleys. For determining this information, systems and methods accordingto at least some examples of this invention use inertial and/or pressuresensing systems within the ball to determine ball speed. Wirelesscommunication capabilities also may be provided within the ball tobroadcast the ball speed information, as well as an exact time of impact(alternatively, this data may be simply stored). Additionally, inertialsensing systems may be provided as part of boot of the players, such asan accelerometer, a piezoelectric element, or other device. In suchsystems and methods, a volley can be determined by detecting coincidentimpacts to the boot and ball of one player, with then an “in-air”signature signal from the in-ball accelerometer. If the next impactregistered by the ball is coincident with an impact to another player'sboot, this then signifies a volley where the ball never touched theground in-between the initial kicker's boot and the receiver's boot. Insuch a situation, the receiver may be credited with a “volley”. Volleysare an important metric because they indicate an ability to keep theball moving in a rapid manner (which may help avoid defenses,particularly when the volley is coupled with a successful pass to ateammate, a scored goal, or other favorable event, which also can bedetected by systems and methods in accordance with at least someexamples of this invention).

FIGS. 46 through 50 illustrate various potential features for detectingand/or measuring various metrics relating to actions involved in sendingthe ball into play after a stoppage of play, such as an out of boundsevent, etc. The features of these “set piece” feature determinationsystems, methods, and metrics will be described in more detail below.

FIG. 46—Free Kick Awarded:

Systems and methods according to at least some examples of thisinvention may determine when a free kick has been awarded. The free kickcan be determined based on the combined technologies explained above forpossession and tackle determination, as well as the technology describedin more detail below for determining whether a set piece exists. Moreparticularly, a free kick can be determined by the following steps:

-   -   a. Possession of the ball is determined and awarded to a first        player.    -   b. A second player comes into the area of the first player in        possession of the ball (e.g., as determined by an attempted        tackle, contested time, player-to-ball proximity,        player-to-player proximity, etc.). This feature also may be        determined, for example, based on person-to-person proximity and        touching of the two people (e.g., as indicated by impact sensors        provided on the players' bodies).    -   c. The ball detects a “set piece” play, as will be described in        more detail below in conjunction with FIG. 48.        The “free kick” awarded metric may be a useful measure of the        effectiveness of a defensive player or other information.        FIG. 47—Free Kick v. Penalty Kick:

Systems and methods for determining approximate flight distance of theball are described above. Additionally, systems and methods fordetermining when the ball has been caught by the goalkeeper aredescribed in more detail below. These features will be useful inautomatically distinguishing a free kick from a penalty kick by systemsand methods in accordance with examples of this invention.

A penalty kick is always kicked from the same spot on the field, where afree kick is not.

Using an accelerometer and/or a combination of pressure sensor and anaccelerometer, ball speed can be calculated. This example aspect of theinvention uses time information from the kick to first impact withinproximity of the keeper, combined with set piece knowledge (as describedin more detail below) to determine if the kick was a penalty kick usingball distance. For example, if after a set piece determination the ballis kicked and comes into proximity of the goal keeper (or in contactwith the goal keeper) within a certain time frame (e.g., depending onthe ball speed), then it may be determined that the kick was a penaltykick. If no goal keeper proximity is detected after a set piecedetermination, or if no goal keeper proximity is detected within apredetermined time (e.g., depending on the ball speed), then it may bedetermined that a free kick occurred.

As an additional feature or an alternative feature, using a possessionor proximity sensing system as described above, the two types of kicksmay be differentiated. For example, a penalty kick, by definition, willnot have other players (either offensive or defensive) within a veryspecific distance from the ball (as determine by the penalty box size).During the flight of the ball, a proximity sensing system (as describedabove) can determine whether the ball passed near any other players onits way to the goal. A free kick will always have defending playersbetween the ball and the goal, and therefore, a shot on goal typicallywill register at least a brief proximity to a defensive player (atminimum) before reaching the keeper. As yet another example,player-to-player proximity detection may indicate two or more players ona team in tight proximity to each other (e.g., when in a wall position,as shown in FIG. 47), which also may be used as an indication that afree kick has occurred.

FIG. 48—Set Piece Shot:

“Set piece,” as used in this context in this specification, refers tothe soccer ball being placed on the ground for an ensuing penalty kickor free kick. It is an important metric for the player to know anddistinguish “set piece kicks,” as these tend to be the more difficultshots on goal during the game of soccer.

Using an accelerometer or other ball mounted inertial sensing system, itcan be determined when a ball is not in motion (or when its motion isslow or minimal). Some more specific examples include, but are notlimited to: a three-dimensional accelerometer in the ball, athree-dimension accelerometer combined with a gyroscope, anaccelerometer in the ball combined with a compass sensor, ball movementspeed and/or lack of rotation matching a player in proximity's speed,etc. One or more of these sensor outputs may be utilized to show theball has been carried and placed, followed by the ball not moving, andthen followed immediately by a kick (matching of boot impact to ballmovement/pressure spike). While this kick could be a corner kick, apenalty kick, or a free kick, the type of kick may be determined, atleast in some instances, by what happens next, e.g., by who's proximityit passes, by the next contact person, the timing between the kick andthe next proximity, etc., e.g., as described above.

FIG. 49—Set Piece Save:

This example aspect of systems and methods according to this inventiondetermine when a kick after a set piece event (e.g., determined asdescribed above) has resulted in a goal keeper save. As noted above, theterm “set piece” refers to the ball being placed on the ground for anensuing penalty kick or free kick, and it may be determined as describedabove.

As a more specific example, a set piece event may be determined bysystems and methods according to this example aspect of the invention inthe manner described above in conjunction with FIG. 48. Once a set pieceevent has been determined, and when the set piece event has includedproximity to the goal keeper, a throw, pass, or drop kick initiated bythe goal keeper may be detected (e.g., as described above and/or in moredetail below) and used as an indication that the goal keepersuccessfully saved the kick resulting from the set piece event (e.g., bya goalkeeper catch or parry event). Various features of goal keeper savedeterminations will be described in more detail below.

FIG. 50—Set Piece Kick—on Goal or not:

Example systems and methods for determining a set piece event aredescribed above. This example aspect of systems and methods according tothe invention uses the previously defined set piece sensing method andadds proximity/possession sensing systems and methods (such as magneticsensing, RADAR, etc.), e.g., like those described above, to determinewhether a set piece kick was “on-goal” or not. As a more specificexample, when a set piece event has been determined, immediatelyfollowed by a kick, which is then followed by ball to keeper proximity,if the next event is a kick or a drop kick by the goal keeper, then aset piece save event may be determined.

FIGS. 51 through 55 illustrate various potential features for detectingand/or measuring various metrics relating to player motion, e.g., duringa game, practice session, training session, etc. The features of thesesystems, methods, and metrics will be described in more detail below.

FIG. 51—Direction of Movement Based on Body Angle:

Systems and methods according to at least some examples of thisinvention will provide information regarding the direction of playermovement, which may be based, at least in part, on the player's bodyangle during the motion. This determination may be made, in at leastsome example systems and methods according to this invention, using an“on body” accelerometer to sense the upper body's angle and translatethis information into a direction metric. For example, when acceleratingor moving in any direction (e.g., forward, backward, to the side, etc.),the upper body tends to lean in the direction of acceleration. Forexample, when accelerating in the forward direction, the body leansforward. This angle and lean helps move the body forward, and the legsfollow. Generally, the greater the acceleration, the greater the leanangle. This same feature also works for back steps and side steps.

Accordingly, by measuring the lean of the body, information regardingthe player's movement direction (and optionally the intensity of thismotion) can be determined. This metric may be useful for determining aplayer's ability (e.g., if an offensive player spends too much timebackpedalling or sidestepping, etc.) and/or ascertaining areas fortraining and game improvement.

FIG. 52—Player “Turn in”:

This example aspect of the invention uses a sensing system on the playerthat determines player speed, such as an inertial sensing system,contact-time based pedometer system, etc., and a player mountedrotational sensor, such as a gyroscope, compass sensor, etc., todetermine the amount of body rotation. Player “turn-in” can be definedas the amount of speed lost by the player during quick directionchanges. This metric may be valuable in the game of soccer as a measureof a player's “quickness” or “agility.” The acquisition of the “turn-in”metric may simply require the measurement of the speed sensing systembefore and after a measured rotation from the rotational sensing system.As one more specific example, the performance metric may be calculatedby subtracting the player speed before the change in direction from thespeed post rotation. Information relating to this metric can then bedisplayed or visualized on a web page or hand-held device (such as amobile phone) and compared with other metrics gathered by the system inprevious and future games. Moreover, information relating to this metricmay be used to develop training programs to improve playerquickness/agility.

FIG. 53—Player “Turn in” on Ball:

This example aspect of the invention is similar to the “turn-in”determination as described above, but additionally includes the metricthat the player is in possession of and/or in proximity to (andoptionally maintains possession of and/or in proximity to) the ball. Inother words, for any measured turn-in events, as described above,another metric can be developed for turn-in events that occur for theplayer while the player is in possession of or in proximity to the ball.This metric may be valuable with respect to the game of soccer as ameasure of a player's “quickness” or “agility” while handling the ballor while closely defending the ball. Information relating to this metriccan then be displayed or visualized on a web page or hand-held device(such as a mobile phone) and compared with other metrics gathered by thesystem in previous and future games. Moreover, information relating tothis metric may be used to develop training programs to improve playerquickness/agility while handling the ball.

FIG. 54—In Shoe Sensor Based Contextual Reporting:

Athletic performance monitoring systems and methods according to atleast some examples of this invention include an in-shoe sensing systemfor measuring speed and/or distance information (e.g., a pedometer typespeed and/or distance sensor). This sensor also may provide contextualinformation about the specific part of sport the athlete is in, e.g.,what types of activities he or she is performing, and this contextualinformation may be used by other portions of the athletic performancemonitoring systems and methods (e.g., on body sensors, etc.) to changethe kinematic models and/or algorithms used to determine the player'srunning speed and/or travel distance.

Output from the shoe based sensors (e.g., accelerometer, force sensors,etc.) may include a “signature” appearance that correlates to the typeof activity being performed by the athlete. For example, the in-shoebased accelerometer output (e.g., the signal shape) may differ dependingon whether the athlete is moving forward, moving rearward, sidestepping, tackling, passing the ball, walking, dribbling, sprinting,slow running, skipping, jumping, sliding, sliding laterally, etc. Byautomatically determining the type of action with which the athlete isinvolved (using the shoe based sensor output), more specializedalgorithms for determining player performance may be called up to enablea more accurate determination of the parameters involved in the player'sperformance. Different algorithms also may apply under other differingcircumstances, for example, different speed and/or distance determiningalgorithms may apply depending on whether the player is on ball or offball.

As one more specific example, because different in-shoe sensor waveformsmay be involved in running forward or backward (e.g., different lofttimes, different pressure profiles, etc.), systems and methods accordingto examples of this invention may automatically determine whether anathlete is moving forward or rearward based on the characteristics ofthe sensor output. Because step size also may differ when moving forwardas compared to moving backward, different algorithms for ascertainingspeed and distance information may be called upon for providing speedand distance data, depending on whether the motion is forward orbackward. Accordingly, this aspect of the invention allows for a moreaccurate determination of speed and/or distance based the determinedmanner in which the athlete is moving.

Moreover, metrics involving the type of movement or other actionsperformed by the athlete may be useful for the player or coach, e.g., toindicate whether an offensive player spends too much time backpedallingor sidestepping, to measure player's efforts and intensity, etc.

FIG. 55—Time Spent on Toes:

In sports and athletic performances, it is often important for theathlete to stay on his/her toes. Being on one's toes generally enablesquicker reactions and/or indicates that the athlete is performing withmore intensity (e.g., while sprinting, an athlete spends more time onhis/her toes than when jogging or walking) Systems and methods inaccordance with at least some examples of this invention may include anin-shoe sensing system that determines the foot angle so as to enable adetermination of the amount of time the athlete spends on his or hertoes. One more specific example of hardware for making this measurementmay include an accelerometer that compares the gravity vector to theorientation of the sensor within the shoe. As another example, the shoemay include a rotational sensing system, such as a gyroscope. The shoealso may contain a measuring system like that described in more detailbelow in conjunction with FIG. 91. The determined information may betransmitted wirelessly to another system for processing and/or stored.The finally determined metric may include, for example, the total amounttime on one's toes, the percentage of time spent on the toes, thepercentage of actual movement (or running) time spent on the toes, etc.

FIGS. 56 through 65 illustrate various potential features for detectingand/or measuring various metrics relating to playing the game of soccer,which may be used and evaluated during a game, practice session,training session, etc. The features of these systems, methods, andmetrics will be described in more detail below.

FIG. 56—Player Posturing:

“Player posturing” is the determination of the ball movement directionas it relates to the player's core facing direction. Using thisinformation, one can determine if a player is in a defensive posture, inan aggressive or attacking posture, etc. The hardware used fordetermining this metric, in at least some example systems and methodsaccording to this invention, include: a directional sensing systeminside the ball (such as a compass sensor, accelerometer/gyrocombination, etc.) to give ball movement direction; and a body-mountedsensor of similar architecture (compass sensor, accelerometer/gyro,etc.) to give player facing direction. The following example steps maybe used to determine a “player posturing” metric:

-   -   1. Using inertial sensors in the ball, the direction the ball is        moving (rolling or in flight) is determined.    -   2. Using a core-mounted sensor (such as gyro, compass, etc.),        the direction the body core is facing is determined.    -   3. Combine these two pieces of information allows a        determination of the relative ball motion to core facing        direction, to help understand contextually what is happening        between the player and the ball.

Additionally or alternatively, core worn sensors between opposingplayers can be used separately (or added to the above) to determine theplayer to player relationships, and therefore enrich the data-set tobuild more confidence on the posturing. For example, the direction ofmotion (and/or the facing direction) of the player in possession of theball can be compared to the direction of motion (and/or the facingdirection) of the defensive player to provide additional informationrelating to this “player posturing” metric.

FIG. 57—Man to Man—Opposing Position:

The determination of what opposing player a particular player had beenmarking can be a useful piece of information when determining a player'sperformance metrics. Systems and methods according to at least someexamples of this invention will use proximity determination methods asdescribed above, but this technology will be used on each individualplayer to provide player-to-player proximity data and information.

As one alternate, if desired, peer-to-peer networking technology may beused to determine and track proximity between players (as well asbetween other elements within systems and methods according to at leastsome examples of this invention). When two players are close enough toestablish a peer-to-peer communication channel (e.g., between devicesthat they are carrying, such as shoe mounted sensors, body core mountedsensors, etc.), this could be established as a proximity event. Bytracking and timing such proximity events, systems and methods inaccordance with these examples of the invention will know which nodes ofthe network (e.g., which other players) a given player was incommunication range with during the majority of the game. As players getfurther away from each other, they may get out of range (and therebybreak the peer-to-peer communication channel). Other ways of determiningplayer-to-player distance may be used without departing from thisinvention. If desired, a “heat map” or other graphic display may beprovided to indicate the opposing team players with which any givenplayer most stayed near during the course of the game, and this willallow a determination of the player being defended or marked during thegame.

As another alternative, some RF modules have RSSI (“radio signalstrength indicators”). RSSI technology can be used on each player todetermine which player was closest to another player for the majority ofthe game.

The Opposing Player metric may be useful, for example, to determine adefensive player's relative performance with respect to the player orplayers that he was defending (e.g., goal scoring effectiveness,successful passing, successful interceptions, etc.).

FIG. 58—Drawing Opposition:

The Man to Man Opposing Position detection capability described abovecan be combined with other metrics to provide additional interestingdata and information relating to soccer (or other sports). For example,combining the Man to Man Opposing Position detecting capability withplayer-to-player proximity detection and player speed determination(e.g., in boot inertial sensors, as described above) may be combined toprovide a metric relating to the ability of a player to draw theopposition. Using an inertial based sensing system, sprints or bursts ofspeed can be measured and combined with the player-to-player proximityto determine if a player is drawing opposition. Example systems andmethods according to this aspect of the invention follow.

First, proximity sensing systems and methods as described above candetermine when two players are near each other. If one player sprintsaway and the proximity detection system shows no players near him andshortly thereafter an opposition player is detected by a proximitysensor again, this suggests that the initial player (the one thatinitially sprinted away) has pulled the opposition players with him.Ball possession determinations also may be used in such systems andmethods (e.g., to determine the player's ability to pull opposition evenwithout the ball).

Additionally, if desired, skill metrics can be created based on theamount of time a player spends within proximity of the opposing player.If a player is meant to be in an offensive position (striker), the moretime spent away from an opposing player the better. On the other hand, adefensive player could be considered better the more time he/she spendsin proximity to the opposition.

FIG. 59—Breakaway Speed:

The Man to Man Opposing Position detection capabilities as describedabove open the door to yet determination of additional information andmetrics. As another more specific example, an inertial sensing systemcan be placed on the cores or boots of the athletes and a comparison canbe made between the relative accelerations of each player at the sametime. Such a system may be used to determine a “breakaway speed” metric.

An example system and method according to this invention for determiningbreakaway speed comprises a speed detection system and combines thisinformation with a wireless communication system to determine coincidentaccelerations of two players. The relative speeds of the two players canbe determined (optionally coupled with directional information), andthis information then can be used to produce a performance metric, e.g.,determining whether the player was faster than the player defendinghim/her (e.g., were you faster than the player that was marking you,etc.).

FIG. 60—Successful Pass:

Completion of a successful pass is incredibly important in the game ofsoccer (and other sports). The following describes an example system andmethod for determining when a successful pass event has occurred (e.g.,a “successful pass” means a pass from one teammate to another).

In this example system and method, output from an impact sensing systeminside the ball (accelerometer, pressure sensor, etc.) is time matchedto output from an impact sensing system inside the boot to enabledetermination of when the ball is struck by a specific foot. A ballproximity sensing system is also employed (magnetic sensing, RSSI, etc.)to enable determination of when the ball is in proximity to a player. Asuccessful pass is determined by systems and methods according to thisexample of the invention in the following steps:

-   -   a. Ball possession by a specific player is determined, e.g., as        described above.    -   b. Kick impacts are registered both on the in-shoe sensor and        the in-ball sensor.    -   c. The ball leaves the proximity of the player that kicked it.    -   d. The ball enters the proximity of a teammate, as determined by        the proximity sensing system.    -   e. Impacts are measured simultaneously by the teammate's boot        and the ball, and a successful pass is recorded.        Determination of the number of successful passes and the number        of unsuccessful passes are useful metrics for evaluating the        performance of the player.

FIG. 61—Give and go:

The “give-and-go” is another common play in the game of soccer. Thefollowing describes one example sensing system, method, and logic thatmay be used to interpret the various sensor signals for determining whena “give-and-go” event has occurred.

Output from an impact sensing system inside the ball (accelerometer,pressure sensor, etc.) is time matched to output from an impact sensingsystem inside the foot to enable determination of when the ball isstruck by a specific foot. A ball proximity sensing system is alsoemployed (magnetic sensing, RSSI, etc.) to enable determination of whenthe ball is in proximity to the player. A give-and-go event may bedetermined in the following manner:

-   -   a. First, ball possession by Player A is determined, e.g., as        described above.    -   b. A kick by Player A is registered on Player A's in-shoe sensor        and the in-ball sensor.    -   c. The ball leaves the proximity of Player A.    -   d. The ball enters the proximity of a teammate, Player B, as        determined by the ball proximity sensing system.    -   e. Impacts are measured simultaneously by Player B's boot and        the ball (i.e., a successful pass is recorded).    -   f. The ball leaves the proximity of Player B (e.g., by a kick by        Player B).    -   g. The ball enters the proximity of Player A and contacts Player        A's boot (another successful pass).

Optionally, a successful give-and-go event may require successful passesfrom Teammate A to Teammate B and back to Teammate A within apredetermined time frame (e.g., in less than 5 seconds). Thedetermination of this event also may require the ball to pass inproximity to, but not into the possession of, a player on the opposingteam (e.g., a “Through Ball/Pass” event, as described below). Successful“give-and-go” events help provide a measure of how well groups ofplayers work together and move the ball on the pitch.

FIG. 62—Through Ball/Pass:

Another interesting metric that may be measured by systems and methodsin accordance with at least some examples of this invention relates todetermination of a “through ball” or “through pass” event. A “throughball” or “through pass” as used herein in this context means that theball is successfully passed from one teammate to another and, during thecourse of the pass, the ball passes in proximity to an oppositionplayer. In some examples of such systems and methods, output from animpact sensing system inside the ball (accelerometer, pressure sensor,etc.) is time-matched to output from an impact sensing system inside theboot to enable determination of when the ball is struck by a specificfoot. A proximity sensing system is also employed (magnetic sensing,RSSI, etc.) to enable determination of when the ball is in proximity tothe players on the field. Then, a “through ball” or “through pass” eventis determined by the following steps:

-   -   a. A player on team “A” is determined to have possession of the        ball.    -   b. Impacts are registered on both the shoe sensor and the ball        sensor simultaneously, registering a kick by a player on team A.    -   c. The ball leaves the proximity of the player that kicked it.    -   d. The ball is determined as having passed through the proximity        of one or more players on the opposing team.    -   e. The ball enters the proximity of a teammate to the original        kicking player (team “A”), optionally, a player that has been        running forward onto the ball.    -   f. The ball sensor and the kick receiving teammate's shoe sensor        simultaneously register an impact and optionally continued        proximity to the teammate (beginning a ball possession event by        the receiving player).        Optionally, if desired, the ball must pass in proximity to one        or more players on the opposing team without the opposing team        contacting and/or possessing the ball. This metric may be useful        for evaluating the performance of players and their passing        skills in a more closely defended environment.

FIG. 63—Pass Distribution:

Pass distribution information also may be an interesting and/orimportant metric for soccer players to consider and evaluate. As somemore specific examples, a determination of a direction of a pass (e.g.,advancing the ball, retreating, etc.) may be useful in evaluating playerperformance.

Output from an impact sensing system inside the ball (accelerometer,pressure sensor, etc.) may be time matched to output from an impactsensing system inside the boot to enable determination of when the ballis struck by a specific foot. Additionally, a rotational sensingmechanism (such as a magnetic sensor, gyro, etc.) inside the ball may beused to enable determination of an absolute direction of movement of theball. A pass distribution metric may be determined through the followingsteps:

-   -   a. Direction of play is determined, e.g., as described herein.    -   b. Possession is determined, e.g., using techniques like those        described above.    -   c. Simultaneous impacts to the boot and ball are recorded and        communicated wirelessly (or stored) to indicate the ball has        been kicked by a specific player.    -   d. Inertial sensors inside the ball are then used to determine        the relative direction of flight of the ball.    -   e. Rotational sensors then record the absolute orientation of        the ball as a result of the kick.    -   f. The two pieces of information from steps d and e can be used        to determine the relative direction of ball flight to the        direction of play determined in step a. This information can be        then compared and evaluated to determine if the kick was        advancing on the opponent or retreating, sent to the player's        right or left, etc.    -   g. The final step is a possession determination awarded to a        teammate, in order to call it a complete and successful pass.

The steps above constitute a determination of a successful pass betweenteammates. If, in step number g, the ball is detected to be inpossession of the opposition team, this is also useful information. Thedirection of all passes made by a player throughout a game can beaggregated to determine pass success/failure rate when trying toadvance/retreat the ball, as well as the amount of time the player movesthe ball forward or retreats over the course of a game.

Finally, if desired, a core mounted directional sensor (e.g., compass,etc.) can be used to determine what movement/facing direction changesoccur as a result of a player receiving the pass. Therefore, it ispossible to use this technology to help give performance metrics, suchas how often the teammate had to come to the ball, wait for the ball, orif the pass was laid out perfectly in front of the player.

FIG. 64—Out of Bounds:

In order for an athletic performance monitoring system and method tounderstand the play of a soccer game, the system and method should nottake into account possession, kicks, and other activities that occurwhen the ball is out of play. The following is an example of a systemand method that may be used to determine when a ball has gone out ofbounds.

Output produced by an impact sensing system inside the ball (e.g.,accelerometer, pressure sensor, etc.) is time-matched to output producedby an inertial sensing system inside the boot to enable a determinationof when the ball is struck by a specific foot, and optionally, to enabledetermination of the path that the foot has traveled. A proximitysensing system also may be employed (e.g., magnetic sensing, RSSI, etc.)to enable a determination of when the ball is in proximity to particularplayers on the field. One example process that may be used to determinewhen the ball has gone out of bounds is as follows:

-   -   1. An individual player possession is determined using        technology/procedures as described above.    -   2. Optional: the ball detects a kick by the simultaneous impulse        on the inertial sensing systems within the boot and the        pressure/acceleration sensing systems in the ball.    -   3. Optional: the ball is detected to be within the radius of        proximity of an opposing player.    -   4. Inertial sensors in the ball detect when the ball has been        picked up (e.g., identifying the low frequency signals as        compared to foot/ground impacts; identifying no motion, slow        motion, or low spin motions for extended play; identifying speed        of motion consistent with player's speed in proximity to the        ball (i.e., the player holding the ball); etc.).    -   5. The ball either detects a throw-in or a set piece play using        previously described methods.        Once this type of “out of bounds” situation is detected, systems        and methods according to at least some examples of this        invention can adjust the various determined metrics, such as        possession time (e.g., by deducting from the determined        possession time for an individual player or team the length of        time between the throw-in or set point event and the previous        kick (which induced the out of bounds event), etc.). Other        metrics also may be adjusted based on “out of bounds”        determinations without departing from this invention.

FIG. 65—Intentional Out of Bounds:

In a specific subset of normal “out of bounds” situations, as describedabove, sensing systems and methods in accordance with at least someexamples of this invention may differentiate situations when a ball hasbeen intentionally kicked against another player to send the ball out ofbounds, resulting in maintaining possession. The same equipment may beused as described above in conjunction with FIG. 64, but additionally,ball proximity to another player and/or ball impact with another playeralso may be detected and relevant to the “intentional out of bounds”situation. The following example process may be used for detecting anintentional out of bounds situation:

-   -   1. An individual player possession is determined using        technology/procedures as described above.    -   2. The ball detects a kick by the simultaneous impulse on the        inertial sensing systems within the boot and the        pressure/acceleration sensing systems in the ball.    -   3. The ball then detects another impact that does not coincide        with a boot impact for any other player on the pitch        (optionally, the ball also may be detected to be within the        radius of proximity of an opposing player).    -   4. Inertial sensors in the ball detect when the ball has been        picked up (e.g., as described above).    -   5. The ball either detects a throw-in or a set piece play using        previously described methods.        Information relating to the ability of a player to induce an        intentional out of bounds situation on the opposing team can be        useful in ascertaining the skill of the player causing the        intentional out of bounds situation (e.g., ball handling skills,        defense avoidance skills, etc.), as well as the skill level of        the defensive player against whom the ball was kicked to produce        this situation.

FIGS. 66 through 75 illustrate various potential features for detectingand/or measuring various metrics relating to goals and/or activities ofthe goalkeeper in the game of soccer, which may be used and evaluatedduring a game, practice session, training session, etc. The features ofthese example systems, methods, and metrics will be described in moredetail below.

FIG. 66—Keeper Recognition:

While systems and methods according to at least some examples of thisinvention may request input or special equipment for the goal keeper, ifdesired, at least some systems and methods according to examples of thisinvention may be capable of automatically identifying which player isthe goal keeper based on detected activities that occur over the courseof a game.

Example hardware for use in recognizing the goal keeper may include: (a)an inertial sensing system on the player (e.g., either on the core or inthe boot) to provide player speed and distance information; and (b) awireless communication system to allow the sensing systems on theindividual players to broadcast their signals/processed data (or storagecapabilities for this data). Then, as one example, the automaticdetermination of the keeper may be accomplished in the following way:

-   -   a. Speed and distance information is collected and considered        for each player on the pitch.    -   b. The keeper, due to his/her position, will do the majority of        his/her movement within an 18 yard box located near the goal.    -   c. After (or during) the game, the data from the sensing system        can be evaluated to understand which player on the pitch moved        the least, and stayed predominantly within an 18 yard box.        Different performance metrics (e.g., the performance metrics        described in more detail below) may be determined for the player        identified as the goal keeper.

As another alternative, if desired, the goalkeeper may be equipped withgloves that have the capability of determining contact with and/orproximity to the ball (e.g., impact sensors, accelerometers,ball-to-glove proximity sensing systems, etc.). Data collected by suchgloves also may be used in various ways for determining various metrics,such as the metrics described in more detail below. As yet anotherexample, systems and methods according to examples of this invention mayallow the various players to enter data identifying their positions.

FIG. 67—Save/Goal Protection:

Systems and methods according to at least some examples of thisinvention may include features to enable determination of goal keepersaves and protection of the goal. This aspect of the invention may beaccomplished using various sensors to determine when a keeper saves ashot on goal. For example, systems and methods according to at leastsome examples of this invention may utilize an inertial sensor on thebody core of the keeper, a ball proximity sensing system, and aninertial sensing system within the ball, e.g., of the various typesdescribed above. A determination of an impact to the ball withsignificant magnitude (e.g., above a threshold level, such as would bepresent in a typical shot on goal, or a header off of a corner kick, forexample), immediately followed by (or simultaneous with) ball proximityto the keeper, followed by a picked up ball, and then a drop kick orthrow, may be used an indication that the goal keeper has saved a shoton goal (and successfully protected the goal). Additionally oralternatively, if desired, the goalkeeper may be equipped with glovesthat have the capability of determining contact with and/or proximity tothe ball (e.g., impact sensors, accelerometers, ball-to-glove proximitysensing systems, etc.), and such contact may be an indication of goalkeeper interaction with the ball. As another alternative, sensor datataken from the goal keeper's body-worn accelerometer could be comparedto sensor data from the accelerometer data in the ball. As the keeperruns or moves with the ball, the two sensors will indicate a verysimilar net path taken. This data can be used to determine possession ofthe ball by the goal keeper.

FIG. 68—Keeper Parry:

This example aspect of the invention relates to systems and methodscapable of determining a “keeper parry” scenario, i.e., a situationwhere the keeper gets his hands (or other body part) on a shot on goal,which deflects the ball out of bounds (e.g., outside the goal, over thegoal, etc.). As a more specific example, using inertial and pressuresensing systems inside a soccer ball, the ball will generally show asofter impact signature on the accelerometer and/or the pressure sensorswhen it contacts a player's hands, as compared to a goal-post impact,kick, or ground impact. This unique sensor signature and determinationof a non-shoe/ground/goalpost impact, combined with detection ofproximity to the keeper, followed by a set piece event (as describedabove, e.g., a corner kick), is a unique sequence of events that onlyhappens when a keeper parry event occurs. Additionally or alternatively,if desired, the goalkeeper may be equipped with gloves that have thecapability of determining contact with and/or proximity to the ball(e.g., impact sensors, accelerometers, ball-to-glove proximity sensingsystems, etc.), and fleeting contact or proximity of the glove to theball may be considered an indication of a keeper parry situation(optionally, combined with some of the other features of this scenariodescribed above).

FIG. 69—Hard Shot Keeper Parry or Catch:

This example aspect of the invention involves determination of a keeperparry event or keeper catch of the ball that has been kicked hard.Defending against a hard shot will typically require improvedgoaltending skills, and the ability to differentiate saves in thissituation may provide an additional interesting metric for coaches orplayers to consider. Systems and methods according to at least someexamples of this aspect of the invention may use inertial and/orpressure sensing systems within the ball to determine ball speed as wellas wireless communication capabilities included with the ball that arecapable of broadcasting ball speed information and impact timeinformation. Furthermore, systems and methods according to at least someexamples of this invention further may include proximity and/orpossession determination technology (such as magnetic, RF, or other)that allows a determination of when the ball is within proximity to (orin the possession of) specific players, and in this scenario, inproximity to or in the possession of the keeper.

The combination of the keeper's ability to catch or parry the ball(e.g., using sensing technology described above) vs. the ball speed canthen be mapped into a player skill metric (e.g., percentage saves ofshots on goals over a predetermined kick speed, etc.). For example, forfaster ball speeds, the keeper's ability to parry or catch the ball canbe considered more skillful.

As another alternative, keeper reaction time can be determined, forexample, by comparing the time of kick with the time of impact by thekeeper's hands. The time difference between the two events can informhow much time the keeper had to react to the shot on goal.

Information relating to this metric can then be displayed or visualizedon a web page or hand-held device (such as a mobile phone) and comparedwith other metrics gathered by the system in previous and future games.Moreover, information relating to this metric may be used to developtraining programs to improve player quickness, agility, and/or reactiontime (if necessary).

FIG. 70—Keeper Advance (Tackle):

This example aspect according to the invention uses a set of sensorsystems on the keeper and in the ball to determine when the keeperperforms a successful tackle, taking the ball away from the opposition.As some more specific examples, systems and methods according to thisaspect of the invention may determine when an opponent has possession ofthe ball, followed by a contested time period between the keeper and theopposing player (e.g., both the keeper and the opposing player in closeproximity to the ball), followed by a dive event performed by the keeper(e.g., determined by an on-body inertial sensing system carried by thekeeper), followed by a picked up ball (e.g., which may be determinedbased on sensors in the keeper's gloves, accelerometer and/or gyrosensors in the ball, etc.). These events, happening in this sequence,are unique to a keeper tackle event. Tracking keeper tackle eventsprovides an interesting and useful metric for evaluating keeperperformance.

FIG. 71—Keeper Dive/Player Dive/Player Jump:

An inertial sensing system, such as a three-axis accelerometer, whenmounted on the body of a player during a soccer match or other activity(especially at the body core), will spend the majority of the time in afairly flat plane of motion (e.g., a certain height off the grounddetermined by sensor mounting location). When the keeper (or otherplayer) dives to the ground, the sensor will make a sharp deviationdownward to the ground, followed by the player standing up and resumingmotion within the original plane of motion. These two events can be usedto determine when the player has made a diving action and/or when he/sheis standing up. This same technology may be used, for example, todetermine when a player has jumped a significant height in the air.

FIG. 72—Drop Kick:

A “drop kick” event (a common event performed by a goal keeper in thegame of soccer) also may be detected by systems and methods inaccordance with at least some examples of this invention. Commerciallyavailable accelerometer technologies today can determine when theaccelerometer (and hence the device with which it is engaged) is in afree-fall condition. Systems and methods according to this example ofthe invention use an accelerometer placed in a ball, in combination withan impact-sensing system in a shoe. These sensors can be used todetermine the following event sequences, which correspond to and may beidentified as drop kick events:

-   -   a. For a direct drop kick (in which the ball does not touch the        ground first): the ball is picked-up, dropped (i.e., detected as        being in free-fall), followed by a kick-impact (ball and shoe        impacts at the same time).    -   b. For a bounced drop kick (in which the ball touches the ground        briefly before being kicked): the ball is picked-up, dropped        (i.e., detected as being in free-fall), makes a small impact due        to contact with the ground, followed by a kick-impact (ball and        shoe impacts at the same time) when the ball is traveling away        from the ground. Alternatively, the ball may experience the        kick-impact at the same time the ball contacts ground.

If desired, a maximum threshold time period may be initiated once theball contacts the ground during which the kick event must be recorded inorder for a successful bounced drop kick event to be counted.

FIG. 73—Shot on Goal that Goes Out of Bounds:

Systems and methods according to at least some examples of thisinvention may utilize a system of sensing elements in the ball (andoptionally sensors in the boot) to determine when a ball goes out ofbounds beyond the goal line (resulting in a goal kick), e.g., due to awide kick or a high kick. The detectable events that enabledetermination of a “Shot on Goal that Goes Out of Bounds” are asfollows:

-   -   a. Coincident impacts to the ball and boot are recorded to        determine that a kick event has occurred.    -   b. The ball is then picked-up (which may be determined, for        example, by detection of a very slow rotational pace and/or low        frequency accelerations using inertial sensing/rotational        sensing methods—the sensor output from a carry event will appear        different from the sensor output from a kick event, e.g., in        ball rotation, acceleration, etc.).    -   c. A set piece event then occurs (and optionally, a kick from        the set-piece event may be detected).

This metric may be useful, for example, to determine offensive playerskill and effectiveness, identifying missed opportunities during a game,defense effectiveness, etc.

As another example, if desired, the goal posts could include electronicmodules thereon that allow proximity detection between the goal postsand the ball.

FIG. 74—Shot on Goal:

An important part of the game of soccer is the shot on goal. Systems andmethods according to at least some examples of this invention includeball mounted sensors and/or player mounted sensors that will allow fordetection of when a shot on goal has occurred. In one example system andmethod, output from an impact sensing system inside the ball (e.g.,accelerometer, pressure sensor, etc.) is time matched to output from animpact sensing system inside the boot to enable determination of whenthe ball is struck by a specific foot. A proximity sensing system alsomay be employed (e.g., magnetic sensing, RSSI, etc.) to enabledetermination of when the ball is in proximity to specific players onthe field. A core-mounted player rotational sensor also may be employed(e.g., compass sensor, gyro, etc.) to enable determination of whichdirection the player is facing as well as relative rotationalinformation. Additionally, an inertial sensing system on the player canbe used to provide additional signals and information. The events thatoccur to determine a shot on goal according to this example of theinvention are as follows:

-   -   a. Possession by a member of the attacking team is determined,        e.g., using techniques described above.    -   b. Signals from the pressure sensor or inertial sensor within        the ball occur simultaneously to signals from the impact sensing        technology within the boot.    -   c. Wireless communication between the boot and ball match the        time exactly, recording the event as a kicked ball.    -   d. Proximity sensing systems record the ball entering the        proximity radius of the defending team's goal keeper.    -   e. Inertial and rotational sensors within the ball record        low-frequency signals that are characteristic of the ball being        held by a person. Alternatively, inertial sensors on the player        correlate closely to the path of travel recorded by the inertial        sensors within the ball, suggesting the ball is being carried.    -   f. The ball is thrown, the ball is drop kicked, or a set-piece        play is executed.

The “shot on goal” determination may be useful for a variety of metricsthat may help determine the effectiveness of a goal keeper, theeffectiveness of one or more offensive players, the effectiveness of oneor more defensive players, team or line up effectiveness, etc.

FIG. 75—Goal Scored:

Systems and methods according to at least some examples of thisinvention also may be able to automatically determine when a goal hasbeen scored. This may be accomplished, for example, by considering, atleast in part, the behavior of the ball when it strikes the net andcomes to a rest during a goal. As a more specific example, the followingevents may be used to determine that a goal has been scored:

-   -   a. Ball possession by a member of the attacking team is        determined, e.g., using one or more of the techniques described        above.    -   b. Signals from the pressure sensor or inertial sensor within        the ball occur simultaneously to the signals from the impact        sensing technology within the boot.    -   c. Wireless communication between the boot and ball match the        time exactly, recording the event as a kicked ball.    -   d. Optionally, proximity sensing systems record the ball        entering the proximity radius of the defending team's keeper.    -   e. An internal accelerometer in the ball recognizes that the        ball has hit the net by producing signals indicative of a slow        stop due to the ball being caught in the net (and optionally a        gravity drop to the ground). This signal or series of signals        will appear different from a more abrupt stop or direction        change resulting from a catch or kick and/or the slow stop        produced as the ball rolls to a stop.    -   f. Inertial and rotational sensors within the ball record        low-frequency signals that are characteristic of the ball being        held or carried. As an alternative, inertial sensors on a player        correlate closely to the path of travel recorded by the inertial        sensors within the ball, suggesting the ball is being carried.    -   g. The ball is carried back to the center circle and is place        like a set piece for a restart to the game by the team that did        not score. (Optionally, other events, like those described        below, may be used as an indicator of play resumption).

The “goal scored” metric may be combined with other metrics, likepossession information prior to the goal (e.g., to determine whichplayer made the goal, assist information, etc.), goal keepereffectiveness, individual player effectiveness (both offense anddefense), line-up effectiveness (both offense and defense), etc.

FIGS. 76 through 83 illustrate various potential features and/orfunctionality of systems and methods according to some example aspectsof this invention relating to the various teams, team metrics, gamefeatures, and the like. The features of these example systems, methods,metrics, and functionality will be described in more detail below.

FIG. 76—Automatic Pick of Team Captains:

On “pick up” soccer matches, there is often the need to choose a captainof each team who will then each choose their players one at a time. Ifdesired, systems and methods according to at least some examples of thisinvention may be programmed and adapted to automatically pick captainsfrom an assembled group of players, e.g., based on one or more metricsrelating to the player of the assembled group of players.

As some more specific examples, systems and methods according to atleast some examples of this invention may utilize the data andcontextual information amassed by the assembled players over multiplegames played. This example system involves nodes on each player thatcomprise the sensing systems described above, as well as a means ofcommunicating wirelessly. One or more metrics for the assembled playerscan then be communicated to a common location (e.g., a cellulartelephone, a palmtop computer, a laptop computer, a sideline computer,one of the player's body mounted devices, etc.) where the data can becollected and compared. Once the devices have communicated relativeskill levels of the assembled players (e.g., by transmitting any of thevarious metric information as described above), the two best players (orany other metric such as the two worst players, the two best passers,the two best (or worst) goalkeepers, etc.) can be chosen to be thecaptains. If desired, systems and methods according to at least someexamples of this invention may determine the best two overall playersand the best two goal keepers and then divide these four players betweenthe teams so that the best goal keeper is on the team of the second bestplayer and so that the second best goal keeper is on the team of thebest player. Any desired way of dividing up the players and/or choosingthe captains may be used without departing from this invention.

As another alternative, rather than simply picking captains or goalkeepers, systems and methods according to at least some examples of thisinvention can assemble, compile, and review the data to determine thefairest distribution of the assembled players among the teams using themetrics that have been amassed over multiple games played using thesensing systems and methods according to this invention.

As yet some additional options, if desired, systems and methodsaccording to at least some examples of this invention that automaticallychoose the entire teams based on the assembled players may performadditional functions as well. For example, any way of advising theplayers of the team on which they should play on may be provided withoutdeparting from this invention. As some more specific examples, systemsand methods according to the invention could send a team indicatormessage to the cell phone or other electronic device of each player(e.g., “You are on Team 1” or “You are on Team 2”). As another option,if desired, the computing system that automatically chooses the teamscan wirelessly communicate with an electronic module provided on agarment or jersey, which can then change color, present textualinformation, or produce other features to show the team assignmentdecisions that were made.

FIG. 77—Determination of Game Start:

Systems and methods according to this invention may determine when agame actually starts (which can be the signal to start accepting datafrom the various sensors, e.g., mounted on the ball, players, goalposts,other equipment, etc.). Any desired way of ascertaining the start of thegame may be used without departing from this invention. As one example,one player or other individual (such as a referee, a coach, etc.) may betasked with manually providing an indication to a computing system as towhen the game has started. As another example, the “game start” eventcan be determined by detection of a set piece event (as described above)within a short time frame after all players (or a majority of theplayers) in the game activate their on-body sensing systems using apeer-to-peer network, followed by a very short pass within team members.

Other ways of automatically determining the start of the game may beprovided without departing from this invention. For example, in someexample systems and methods according to the invention, all players onthe field that are using the sensing systems and have on-body inertialsensing systems in accordance with this invention will be incommunication with one another over a peer-to-peer network. Thebeginning of the game is one of the very few situations where theplayers are all standing reasonably still and two players on the sameteam are in close proximity to the ball. Detection of this type ofactivity or situation, followed by sudden and simultaneous movement byalmost all of the players, may be used as an indication that the gamehas started.

As another example, in some systems and methods according to examples ofthis invention, all (or many) players may have an on-body sensing systemthat determines the orientation of the core of the body. Each sensingsystem may be connected via a wireless communication method that definesa peer-to-peer network. In such a system, all the modules can broadcastthe direction on the field in which each person is facing. Combiningthis facing direction information (all team members facing the samedirection, which is opposite to the direction that the opposing teamfaces) with detection of a set piece event, and optionally adding theproximity information described above where two players of the same teamare standing within close proximity to the ball, can be used as anindication that the start of the game is about to occur (or has occurredonce the initial kick is sensed).

As yet another alternative, the start of the game may be determined bysubstantially simultaneous movement by each player from a generallystanding still position, due to the kickoff (optionally, correlated to aset piece event and/or an initial kick detection event, as describedabove).

FIG. 78—Direction of Play:

For various metrics relating to the play of soccer (e.g., to determinethe course of play, to determine whether a team tended to be attackingor defending, to determine various skill metrics, etc.), the directionof play for each player and/or each team may be a useful piece ofinformation for sensing systems and methods according to at least someexamples of this invention (e.g., so the systems and methods know whichgoal each team and player is defending and which goal each team andplayer will approach to score). Systems and methods according to atleast some examples of this invention may determine the direction ofplay automatically, e.g., based on the movements of the various playersover time. Determination of the direction of play according to at leastsome examples of this invention may utilize a body-mounted sensor withdirection sensing capabilities (e.g., a compass sensor,accelerometer/gyro, etc.) to determine the direction that a player isfacing at any given time. For such systems, direction of play may bedetermined by the following steps:

-   -   a. Multiple players on the pitch have sensing systems that        include wireless communication means for sharing directional        information.    -   b. Sensor signals are read on each individual player and are        broadcast wirelessly to all sensor nodes (e.g., on each player).    -   c. The nodes are all integrated over the course of play to        determine which players spend most of their time facing a        particular direction.    -   d. Teammates will all share a similar bias toward facing the        opposition goal.

This technology may be used to automatically determine which players areteammates. Additionally, as noted above, it may be useful fordetermining various metrics relating to the game, both on a team leveland on an individual level. For example, offensive players that spendtoo much time facing their own goal may not be as effective as offensiveplayers that spend less time facing their own goal. This data may alsobe used to determine which team seemed to play a more “attacking” gamev. which team seemed to play be more defensive.

FIG. 79—Direction of Play Alternates:

FIG. 79 helps illustrate various alternative features for automaticallydetermining direction of play (or information that may be used inautomatically determining direction of play and/or automaticallyascertaining teammates) that may be used in systems and methodsaccording to at least some examples of this invention. For example,knowledge of the “start of game” metric, as described above, can be usedto instantaneously look at the output of the core sensors to understanddirection of play of individuals and/or teams and/or automaticallydetermine the teammates. More specifically, in general, at the start ofthe game, members of each team will face the opponent's goal. Therefore,the individual facing direction information at the beginning of thematch for each individual may be stored, and this information can beused, at least in part, to determine the direction of play for eachindividual and/or the members of each team.

As another alternative, ball possession information (and the sensorsthat collect individual player possession information) may be used incombination with the direction facing sensors described above to enabledetermination of which direction the players are facing when on-ball,and the majority of dribbling performed by that player will be presumedto be driving toward the opposition goal.

As another alternative, pass sensing technology (e.g., as describedabove) can be used to determine a general pass direction bias,optionally combined with the length/direction of passes, to enable adetermination which direction a particular team or individual is mostoften trying to move the ball. This directional information may bepresumed to be oriented toward moving the ball toward the oppositiongoal.

Another potential alternative for automatically determining theindividual and/or team direction of play (and optionally the identity ofteammates) may take place during “set piece” plays. More specifically,during set piece plays, the majority of each team's player's will befacing toward the opposition goal. Directional sensors can combine withdetermination of a set piece condition (e.g., as reported by the ballvia a wireless network, e.g., using technology described above), whichcan then be used to trigger a communication of all players' facingdirections by the core-worn sensing systems.

As yet another potential option, during long dribbles, the body coreworn sensor on the individual player will tend to report movement towardthe opposition goal. This can be either an inertial sensor system(accelerometer, etc.) or a rotational sensor (gyro, compass, etc.), asboth may be capable of reporting a movement/facing direction biasedtoward the opposition goal.

The various automatic direction and/or teammate recognition technology,as described above in conjunction with FIGS. 78 and 79, may be usedindividually or in any desired combination to provide data relating toand useful in the final determination of an individual and/or playerdirection of play and/or recognition of teammates.

FIG. 80—Teammate Recognition Using Pass Distribution During a Game:

This aspect of systems and methods according to at least some examplesof this invention uses the pass distribution technology previouslydescribed (see FIG. 63). By aggregating the pass distribution data overtime (e.g., via wireless communication between sensor modules), systemsand methods according to at least some examples of this invention maydetermine the people that are most frequently passed to by a particularplayer, and thus the systems and methods may conclude that thesefrequent pass recipients are teammates of the passing player. During thecourse of a game there may be multiple pass interceptions, butpresumably, the dominant number of passes that occur will be to aplayer's teammates. Over time, a pattern will emerge that will allow thesystem to dynamically figure out who is on the same team, and who isnot. Player-to-player and player-to-ball proximity information also maybe used in this aspect of the invention, e.g., this data may betterallow a determination of whether the passing player tends to try to passto an individual or whether the passing player tends to send passes soas to avoid an individual.

Alternative technology may be provided that allows players to manuallyenter the team on which they play (e.g., by input to their body wornsensors, by selection from a menu, etc.).

FIG. 81—Determination of Team Based on Object Orientation:

Various examples of ways of determining which players are on which team(or at least data relating to this determination) are described above.Additionally or alternatively, systems and methods according to at leastsome examples of this invention may use the orientation of the receiversystem (or any component of the system) to determine or as an indicatorof which team a particular player is on. Because the game of socceralways involves only two teams, this determination or indicator systemmay be binary.

Various binary indicators may be provided without departing from thisinvention. As one example, using an accelerometer or other inertialsensing system, the gravity vector may be used to determine theorientation of the object. As another example, a pocket or clip that isintended to house at least some part of the sensing system may have amagnet embedded in it, and this magnet may be sensed by a Hall-effectsensor, reed switch, or similar to determine object orientation. As someexample, the location of the magnet could be in a plastic housing, oreven embedded into an apparel pocket. As another alternative, a passiveelement, such as a ball bearing or similar object, may be pulleddownward by gravity, making an electrical contact with two electrodesinside the object. The side of the housing or other object toward whichthe ball bearing is pulled by gravity can be used as an indicator of theorientation (and therefore team) of the object. The players could wearthe various sensors or the housings therefor in one orientation on oneteam and in the opposite orientation on the other team.

FIG. 82—Determination of Team Using Ball Proximity/Passing:

Aspects of this invention, as described above, may include proximitysensing systems in the ball, as well as inertial/impact sensing systemsin both the ball and the boot. As another feature, systems and methodsaccording to at least some examples of this invention may use theability of the ball to know when it is in tight proximity or know when asimultaneous impact event occurs between the boot and the ball, whichmay be communicated wirelessly, signaling the ball's presence at thefeet of a particular player. This example feature according to theinvention uses a simple algorithm that allows the system to learn theteams. For example, prior to the start of the game (or at some otherdesired time), the ball may be simply passed around to each member of ateam, signaling their status as teammates. This example system andmethod can then use the “passed around” players as one team, and anyother players the ball comes in proximity to can be assumed to be on theopposing team.

Alternatively, if desired, a controlled behavior (such as squeezing theball, picking the ball up, throwing the ball, etc.) can be used tosignal the “transition” from passing around between the players on team#1 to passing the ball around between the players of team #2, and inthis manner the ball can positively identify the various members of eachteam, e.g., before the game begins.

FIG. 83—Use of Pass Frequency to Determine Teammates:

This aspect of the invention uses the technology described above todetermine when a successful pass has been made, but it but removes theknowledge of knowing teammates at the start of the game. If desired,systems and methods according to examples of this invention canautomatically determine the teammates using pass frequency information.In this example system and method according to the invention, the systemwirelessly communicates whenever the ball has traveled from one playerto another, regardless of team. Throughout the game, patterns willemerge between certain players, and the pass frequency between playerson the same team should be much higher. Statistical predictors can thenfigure out which 11 players (or other number of players) are most likelyon the same team by evaluating the frequency of passing among them (manypasses between two individuals most likely identifies them asteammates—two players cannot be that bad to always kick interceptedpasses to the same person). Player-to-player and player-to-ballproximity information also may be useful in this determination.

Pass frequency features can be used in other manners in systems andmethods according to examples of this invention, if desired. Forexample, an individual player's “preferences,” such as which players arepassed to more often by a particular player, can be identified andvisualized online for improvement suggestions. As a more specificexample, if a mid-fielder is always passing to the left side, he/she maybecome more predictable to the opponent. A coach noting or informed ofthis preference or tendency can develop drills for this player to helpimprove his/her skills and confidence in passing to the right side ofthe field.

Additionally or alternatively, if the speed of the player during thepassing is added to the above pass frequency information, the system andmethod can be improved. Pass accuracy may change based on player speed.So added weight in the algorithm can be placed on passes that occur whenplayers are moving at relatively low speeds (as compared to higherspeeds). This may be most evident, for example, when the players passthe ball around the backfield, trying to create space within the fieldto open up a player for a pass near the opponent's goal.

FIG. 84—Post Game Concepts

Various post game features may be made available by systems and methodsaccording to examples of this invention, e.g., such as displaying dataand various metrics regarding player performance as described above. Ifdesired, systems and methods according to at least some examples of thisinvention may allow players to gather and play some “quick games” usingdisplay devices immediately after the game. For example, the variousplayers could gather after the game (e.g., on one team, both teams,portions of either team, etc.) and the data collected for these playersmay be combined (e.g., via wireless communication technology,peer-to-peer connections, etc.) to enable the players to compare andcontrast their performances over the course of a game, workout, orpractice session. Examples of the data that may be determined anddisplayed after the game in a quick gathering of players (e.g., on oneor more player's cell phones, handheld computing devices, etc.) include,but is not limited to identification of: Who had the longest successfulpass? Who reached the fastest speed on/off ball? Who was the best passer(e.g., most passes, fewest interceptions, highest successful passpercentage, etc.)? Who was the workhorse (e.g., who ran farthest, whohad most possession time, etc.)? Who had the fastest kick? Who had themost tackles? These metrics, quick games, and competitions can bedisplayed on an LCD or similar display immediately following the game(or at any other desired time), e.g., giving the system a richerexperience with immediate feedback after the game has been played (oreven during the game). The data displayed may include only data amongthe players gathered at the end of the game for this type of session, orit may include data collected from all of the players by systems andmethods according to this invention.

FIGS. 85 through 93 illustrate various potential features and/orfunctionality of systems and methods according to some example aspectsof this invention relating to the various miscellaneous metrics, gamefeatures, and the like, including various uses of magnetics and magneticproperties. The features of these example systems, methods, metrics, andfunctionality will be described in more detail below.

FIG. 85—Electromagnetic Coils in Ball:

This example aspect of the invention uses coils with pulsed currentloads placed inside the ball to create a magnetic field that can bedetected by sensors outside the ball. Adding a pulsed magnetic field canallow sensing mechanisms in accordance with some examples of systems andmethods of the invention to filter for a very distinct signature, givinggreater range/proximity detection (e.g., it allows body mounted detectorsystems to look for specific signal patterns representative of the balland/or provides better ability to filter out “noise”). As anotherpotential option, if desired, coils with different pulsation rates canbe placed throughout the ball to allow sensors (e.g., body mountedsensors, shoe mounted sensors, etc.) to detect specific places on theball, as well as the direction of rotation, based on the sequence of themagnetic pulse rates detected. This data may be useful, for example, todetermine features of kick length, pass length, and/or other performancemetrics.

FIG. 86—Juggling:

This example aspect of the invention uses the previously describedintegration of magnetic coils and sensors in the ball combined withsensing elements in the boot to detect very close proximity to the ball.Additionally, inertial or pressure sensors may be provided within theball to detect an impact. When an impact is detected by the ball, themagnetic sensors also can be polled to understand if there was asimultaneous impact or close proximity to the boot, and such a systemcan wirelessly communicate (or store) the number of times in a row theball was “juggled” by a player.

Alternatively, impact sensing elements in the shoe (e.g., accelerometer,piezo element, etc.) may be combined with inertial or pressure sensingelements in the ball. The simultaneous impact to the ball and shoedenote a kick, and wireless communication between the two systems may beused to determine how many times in a sequence the ball was kept in theair without impacting another surface, giving the player the number oftimes the ball was juggled. Additionally or alternatively, if desired,time between impacts, impacts with player's knees, and/or other featuresmay be factored in and considered in determining whether a jugglingevent has continued.

FIG. 87—Ball Creates Magnetic Field Proportional to Pressure:

Systems and methods according to this example of the invention includean electrical, electro-mechanical, or mechanical system inside a soccerball that creates a magnetic field that is proportional to the pressureinside the ball. The magnetic field generated then can be sensed byexternal sensors, such as sensors on the boot and/or body core mountedsensors. Examples of implementation and use of this example aspect ofthe invention include, but are not limited to, ball proximity detection(when kicked), detection of internal pressure using external sensing,kick speed, kick force, kick distance, etc.

FIG. 88—Integration of Magnets into Apparel for Ball Detection:

Another potential feature of systems and methods according to at leastsome examples of this invention relates to the use of magnets (eitherpermanent or electro-magnets) and their integration into apparel for asoccer player. The magnets are placed in locations which allow amagnetic sensor within the ball to detect their field, and as suchdetect what part of the body had just interacted with a ball. As a morespecific example, the chest is used in the game of soccer to trap orstop a highly-lofted ball. Upon close proximity to the garment, the ballmay detect the magnet in the clothing and knows which part of the bodyis closest (e.g., the magnet could be provided in shirt to demonstrateand detect chest/shoulder control, in the shorts to demonstrate thigh orknee control, in a headband or hat to demonstrate head control, etc.).Alternatively, if desired, the magnet could be included in the ball andthe sensor mounted on various articles of clothing and the data could betransmitted or stored in the article of clothing.

As another alternative, if desired, inertial and/or pressure sensingsystems provided inside the ball may activate/trigger the magneticdetection sensors when an impact is recorded, allowing the power systemto save battery power and gain efficiency.

FIG. 89—Shoe Power Plate:

This aspect of the invention uses a fluidic material that hardens whenexposed to a magnetic field. Fluid pockets are created within the shoeand/or protective gear (such as a shin guard, etc.), and the fluidincluded in the pockets remains viscous and soft until a magnetic coilresiding underneath or on top of the pocket energizes. This action makesthe material very hard, which can protect the foot, provide a harderkicking surface (to produce greater shot power), etc. Magnetic “smart”fluids, also called “magnetorheological fluids” are known and used inthe vehicle suspension arts and as “liquid body armor” (e.g., forbulletproof vests).

Alternatively, if desired, the fluidic pockets need not have a magneticcoil underneath them, but rather the ball may be adapted to containmagnets that, when in close enough proximity to the fluid, change thestate of the fluid, making the boot hard. As another alternative, ifdesired, a combination of the sensing systems, e.g., as described above,can offer contextual information to a processing system provided in theshoe, which in turn can activate magnetic field generators (e.g., alsoin the shoe), which can actively change the hardness and flexibility ofthe shoe based on real-time information about the game. Alternatively,the shoe can use skill-based metrics gained from previous contests tounderstand what kind of player the athlete is, and how a shoe may betterserve the specific needs of the player.

FIG. 90—Shin Protection Plate:

Aspects of the “shoe power plate” technology described above inconjunction with FIG. 89 may be used in other environments as well. Forexample, this same type of magnetic “smart” fluid or magnetorheologicalfluid may be provided in a pocket of a sock or other clothing tofunction as protective gear (such as a shin guard, etc.). If desired, anopponent's shoes may be equipped with a magnet or magnetic forcegenerating system which would trigger/activate the magnetorheologicalfluid when the shoe closely approached the protective gear. In thismanner, the sock or other item may conform well to the wearer's body (sothat it is comfortable and stays in place) during normal use and onlybecomes hardened when a magnet equipped boot (or the ball) approaches.

FIG. 91—Magnetic Coil to Sense Shoe Properties During Running:

This aspect of the invention involves placing a coil of wire inside ashoe, as well as a permanent magnet that passes through the coil,generating a current flow through the coil. This current flow then maybe used to sense the “contact time” of when the shoe is on the ground.More specifically, when running, the shoe will flex, which through amechanical mechanism moves a magnet within the coils generating thefield. When a runner is running, the shoe will flex until a “toe off”event, and then while in the air the shoe will return to steady state(e.g., a flat sole). Then, after a “heel strike” event occurs, the shoewill begin to flex again, moving the magnet within the coil. These twosignals, from the heel strike and the toe off events, can be used todetermine when the shoe is on the ground and when it is in the air. Thisinformation can be used, e.g., with conventional pedometer type speedand distance determination algorithms, as data useful in determiningplayer speed metrics, which can be integrated to get a player distancemoved metric.

FIG. 92—Magnetic Sensors Coming on Pitch Turns on Body Sensor:

This example aspect of the invention uses a magnetic sensor in the bootor on the player's body (e.g., sensors already provided forplayer-to-ball or player-to-player proximity detection or for any of thepreviously described purposes) to act as a switch to prepare the systemfor the start of the game. For example, magnetic mats (or cones or otherstructures) may be provided at the side of the pitch, and as the playersapproach and enter the field, they will pass over/through this thesystem. This action may be used to turn on the system and get it into a“ready” state for the start of the game. The system can then be startedwhen a game start event is detected (e.g., as described above), or whena player manually activates the system at the start of the game. Themagnetic field also could be directionally varied (e.g., change instrength over the course of its length) so that systems and methodsaccording to this aspect of the invention can ascertain whether theplayer is entering or exiting the field.

FIG. 93—Magnet in Ball Pulls Up Magnetic Sensor Switch in Shoe:

This aspect of the invention may be used, for example, as an alternatesystem in determining player-to-ball proximity and/or player possessionas described above. Systems and methods according to this example of theinvention use a magnetic switch in shoe that moves to signal proximitywhen the magnets in the ball come close. As an example, as illustratedin FIG. 93, a reed type switch may be provided in the shoe that makescontact with an electrical contact provided in the shoe when a magneticsource provided in the ball induces the reed portion of the switch tomove upward or downward. When the magnet in the ball is out of range ofthe switch, the reed returns to its neutral, un-contacting position.Thus, data collected resulting from contacts between the reed switch andthe contact in the shoe can be used to determine and count interactionsbetween the ball and shoe (and thereby provide information regardingproximity to the shoe and/or ball contact with the shoe (e.g.,possession, passes, juggling, etc.)).

FIG. 94: Field Location “Heat Map”:

If desired, systems and methods according to at least some examples ofthis invention may produce a field location “heat map” that indicateswhere on the field the player spent time and, optionally, an indicatorof the amount of time spent on that portion of the field. FIG. 94illustrates an example field “heat map” that may be generated usingsystems and methods according to at least some examples of thisinvention. As shown in FIG. 94, the representation of the soccer field(which may be provided on any desired type of display device, e.g., asdescribed above) may include various zones or regions that indicatewhere the player spent his or her time during the course of the game.The colors of the various zones may provide an indicator of the amountof time spent within that zone. This type of information may be useful,for example, by a coach and the player, to determine how well the playerstays in position and/or when/if the player spends time outside of thedesired or optimal positions. This information also may be useful as anaid for determining whether a player or team is in more of an attackingor defending posture. If desired, the “heat map” may be capable ofdisplaying player positioning during an entire game or practice session,during any desired portion of a game or practice session, and/or evencomparing player performance from one game to the next (e.g., byoverlaying one heat map on another).

Any desired type of player location determining systems and methods maybe used without departing from this invention, such as GPS. As anotheralternative, the initial player location of the field may be entered,e.g., by the player starting at a fixed location for his/her position,and then systems and methods according to aspects of this invention maytrack the player's location from this initial starting location, e.g.,using one or more of: an accelerometer, a gyroscope, a compass, etc. Asyet another alternative, player location may be determined automaticallyover the course of a game, e.g., by noting the player's tendency toavoid going over end lines and side lines, the player's generalpositions and movement on the field may be determined based onapproximate determined locations for the end lines and/or the sidelines. As yet another example, the general heat map may be generatedwithout reference to a location on the field, and after the fact theuser could anchor the heat map location with respect to a representationon the field, e.g., based on knowing an approximate location where theystarted or ended the game, based on their position, etc.

Also, if desired, the heat map may include information regarding ballpossession. As a more specific example, if desired, a special heat mapmay be developed and presented to identify locations on the field wherethe player had possession of the ball. This heat map may includedifferent colors to indicate the number ball possessions at theindicated location, the time of possession at the indicated locations,etc.

Other Information:

As noted above, systems and methods according to at least some examplesof this invention will be capable of determining when a ball is sent outof bounds. Data to assist in evaluating and determining this feature mayinclude, for example, data indicating that the ball has decelerated,data indicating that the ball is not rotating (e.g., being carried), ordata indicating that the ball is moving slowly (e.g., being carried),etc. Optionally, this deceleration, non-rotation, and/or slow motionactivity may be required to last for a predetermined time period (e.g.,at least 2 seconds, at least 3 seconds, etc.). Once it is determinedthat the ball is out of bounds, systems and methods according toexamples of this invention may work backwards to subtract accumulatedpossession time (e.g., individual or team) from the time stamp of thepreviously ascertained and recorded kick (i.e., the last “in bounds”kick).

Also, as noted above, systems and methods according to at least someexamples of this invention may know or be capable of determining whentwo or more players are located within close proximity to the ball.During this time, neither player may be considered as being in clear“possession” of the ball. This time also may be categorized by systemsand methods according to examples of this invention as “contested time.”A determination of “contested time” may trigger a stop in accumulationof team and/or individual possession time (optionally, depending onwhether the opposing player contacts the ball during the contested timeor whether the initial party determined to be in possession of the ballmaintains the ball free from contact of or proximity to the other playerduring the contested time). A new “possession time” may begin (foreither team or any present individual) after the “contested time” periodends. Optionally, if desired, an individual's and team's possession timecould continue during a contested time period, e.g., at least until theopposing player contacts the ball, or until the opposing team clearlygains possession of the ball. Contested time also could accrue when twoplayers reach a loose ball at or near the same time (i.e., when no onehad clear prior possession, such as when the ball moves from onecontested time situation to another).

While many example systems, methods, features, metrics, and aspects ofthis invention have been described in conjunction with the game ofsoccer, aspects of this invention also may be extended for use in avariety of other sports, such as football, basketball, lacrosse, tennis,baseball, rugby, hockey, field hockey, cricket, and golf.

III. Exemplary Embodiments of Passive Tag for Use with FrequencyDoubling Possession Detection System

FIG. 95 shows an exemplary embodiment of passive frequency doubler tag9500 that may be embedded on a puck or ball, e.g., soccer ball 1200 asshown in FIG. 12. With some embodiments, tag 9500 operates at a basic(fundamental) frequency (e.g., 2.4 GHz) and a second harmonic frequencythat is double the first frequency (e.g., 4.8 GHz). While tag 9500 mayhave a reduced range compared with an active tag because of doublerfrequency conversion efficiency, tag 9500 typically does not require anexternal power source for frequency doubler circuit 9501.

While tag 9500, as depicted in FIG. 95, doubles the transmittedfrequency, a tag on the ball may transform the frequency of thetransmitted signal in another predetermined fashion. For example, thetag may triple the transmitted frequency or may add a predeterminedoffset to the transmitted frequency.

The frequency doubler tag 9500 comprises an antenna 9502 and frequencydoubler circuit 9501. Performance monitoring system (e.g., system 100 asshown in FIG. 1) may include a transceiver embedded into a soccer shoe(e.g., shoe 104 or on the player's body) and frequency doubler tag 9500that may be embedded in a soccer ball. Frequency doubler tag 9500 in theball receives a signal from the shoe at a specific frequency andbandwidth and reradiates the signal's second harmonic. When detected bythe on-body transceiver, the propagation delay of the received secondharmonic signal may be converted into another signal with a frequencythat is proportional to the distance between the shoe and the ball. Theperformance of the system is typically affected by the gain of antennaor antennas in the ball and the shoe. To achieve the maximum range atany relative shoe/ball orientation, antenna 9502 and the antenna in theshoe should have uniform omni-directional patterns.

Frequency doubler circuit 9501 follows a non-linear square lawrelationship between the amplitude of the signal and the generatedsecond harmonic. With this relationship, as the signal decreases by 10dB, the resulting second harmonic signal decreases by 20 dB.Consequently, antenna efficiency is often important. The antenna patternshould be uniform to avoid orientations with lower range. Low ‘Q’broadband width element types should be selected to avoid gain reductiondue to detuning in the typical soccer ball environment.

FIG. 96 shows a two-element sinuous antenna 9600 that may beincorporated with frequency doubler tag 9500 in accordance withembodiments of the invention. With some embodiments sinuous antenna 9600has a broad frequency range and planer structure needed to fit in thespace constrained area on ball 1200. As shown in FIG. 96 antenna 9600comprises elements 9601 and 9602 through feed 9603, although otherembodiments may utilize a different number of elements, e.g., fourelements. A matching circuit (not explicitly shown) may be insertedbetween sinuous antenna 9600 and frequency doubler tag 9500, wheresinuous antenna 9600 typically has a balanced input. However, with someembodiments, frequency doubler tag 9500 may directly feed into sinuousantenna 9600 by adjusting antenna 9600 to have an impedance sufficientlymatched to that of tag 9500.

With some embodiments, sinuous antenna 9600 has a diameter ofapproximately 3 inches; however, antenna may be redesigned to fit intothe 2 inch diameter area. With some embodiments additional element typeswere designed and simulated to provide alternatives to the sinuouselements. One characteristic of the antenna that may significantlyaffect system performance is the interaction between the antennaimpedance of antenna 9600 and frequency doubler circuit 9501. Alternateantennas may be designed with different terminating impedances at boththe fundamental frequency (approximately 2.4 GHz) and the secondharmonic frequency (approximately 4.8 GHz). As will be discusseddifferent antenna element types (e.g., crossed magnetic dipole 9900 andturnstile dipole 10200 may be selected to implement an alternativeantenna for antenna 9600.

FIG. 97 shows an antenna plot for a two-element sinuous antenna atapproximately 2.45 GHz in accordance with embodiments of the invention.Frequency doubler circuit 9501 receives a received signal fromtransmission element 110 (as shown in FIG. 1) through antenna 9600 atthe fundamental frequency.

FIG. 98 shows an antenna plot for a two-element sinuous antenna atapproximately 4.8 GHz in accordance with embodiments of the invention.Frequency doubler circuit 9501 transmits a transmitted signal toreceiver 108 though antenna 9600 at the second harmonic frequency.

FIG. 99 shows crossed magnetic slotted dipole 9900 that may beincorporated with a frequency doubler tag 9500 in accordance withembodiments of the invention. Crossed magnetic slotted dipole 9990incorporates slots 9901-9904 to appear as an inverted image of a dipoleantenna. With an embodiment, dipole 9900 has a low profile with athickness of approximately 0.002 inches, a high characteristicimpedance, a broad bandwidth, and omni-directional characteristics.Crossed magnetic dipole 9900 typically presents higher impedances atboth the fundamental and the second harmonic frequencies while turnstiledipole (as shown as 10200 in FIG. 102) typically presents low impedanceat both the fundamental and the second harmonic frequencies. Magneticdipole element 9900 is typically less sensitive to impedance variationdue to the presence of near field surfaces and objects when compared toturnstile element 10200. Sinuous element 9600 typically presents higherimpedances at both the fundamental and the second harmonic frequencies.However, because of the compression to the 2-inch diameter from the 3,inch diameter sinuous antenna 9600 typically presents a low highlyreactive impedance at the fundamental frequency and a high impedance atthe second harmonic frequency. The impedance at the fundamentalfrequency may be compensated by adding matching circuit components.

The relative impedance of sinuous antenna 9600 may be less affected bynear field surfaces and objects due to its broadband low Qcharacteristics. Sinuous antenna 9600 typically provides the mostomni-directional pattern of total gain with respect to antennas 9900 and10200.

FIG. 100 shows an antenna plot for crossed magnetic slotted dipole 9900at 2.45 GHz, while FIG. 101 shows an antenna plot for crossed magneticslotted dipole 9900 at 4.9 GHz in accordance with embodiments of theinvention.

FIG. 102 shows turnstile dipole 10200 that may be incorporated withfrequency doubler tag 9500 as was previously discussed. FIG. 103 showsan antenna plot at 2.45 GHz, and FIG. 104 shows an antenna plot forturnstile dipole 10200 at 4.9 GHz. With some embodiments, turnstiledipole 10200 has a thickness of approximately 0.002 inches, a width of4.25 inches, and a length of 2.62 inches.

Frequency doubler circuit 9601 may be designed using Schottky diodeshaving a low barrier voltage. Several approaches may be considered thathave different conversion efficiencies, circuit complexities, sizes andtermination impedances. For example, a matching circuit may be insertedbetween doubler circuit 9501 and antenna 9502 to better match impedancesbetween circuit 9601 and antenna 9602 at the fundamental frequency andthe second harmonic frequency. The performance impact to conversionefficiency due to termination impedance and the interaction betweenantenna 9502 and frequency doubler circuit 9601 layouts may bedetermined by concurrent simulation. The selection the frequency doublerdesign may be based on reliability testing rather than optimization forconversion efficiency.

The mechanical construction of frequency doubler tag 9500 into the ballmay be focused on reliability. The reliability of tag 9500 may be anarea of concern during both installation into a ball and use. Theselection of materials and construction typically impacts reliability.Due to the complexity of embedding a tag in soccer ball 1200, testmachines may be used to induce failure and reveal weak points in theconstruction. In addition, soccer game play may be used as the finaltest of the best performing tags embedded in balls. To reduce the numberof soccer balls needed for testing, multiple antenna tags may beinstalled in each ball.

The material selection and installation methods may be important areasin the construction analysis. The space allocated for tag 9500 in thesoccer ball top level assembly is a slightly curved area on one of thecarcass panels with a diameter less than 2.1 inches. The 2.1-inchdiameter area may undergo extreme flexing and folding when the ball isin use. Given these constraints, printed circuit board (PCB) materialand assembly processes should be reviewed for implementation. With someembodiments, planar antenna elements may be implemented using standardPCB construction methods.

With some embodiments, materials with acceptable properties, processes,lead time and cost include 4 mil thick FR4 PCB and 2 mil flex circuitPCB. The bottom surfaces of antennas 9502 have no components and are asmooth surface with a uniform solder mask. To prevent soldered jointsfrom cracking during ball flexing, a stiff reinforcement coating such asResinLab EP965 and/or a resin stiffener may be added to the top surfacearound the components. The reinforcement coating or stiffener may be assmall as possible to minimize the stress induced during flexure andlimit the potential for the reinforcement from failing. To mitigatepotential reinforcement failure (delamination or cracking of thereinforcement coating on the circuit board material), a material withlower durometer may be used in some embodiments, e.g., Humiseal 1A33 orDow Corning 1-1277.

Also, the adhesive used to hold tag 9500 to the carcass may inducestrain during flexure of the tag material/conformal coating or may cracksolder joints if the PCB material stretches. The adhesive may be appliedover a small surface area to minimize potential strain on the tagmaterial or copper traces. Possible adhesives include barge, 3M 300LSE,scotch weld epoxy adhesive 2216, Scotch weld rubber adhesive 1300, orLoctite 330. An alternative approach that avoids potential adhesivetransferred strain comprises a fabric or latex pocket to hold antenna9502. The pocket may be made with a known ball construction material andadhesive.

FIG. 105 shows system 10500 for performance monitoring system 100 (asshown in FIG. 1) in accordance with embodiments of the invention.Component areas of the transceiver architecture in shoe 104 includeradio section 10501, microcontroller 10502, power management (notexplicitly shown), and antenna 10504. Tag 10505 is typically located atball 130 as shown in FIG. 1.

System 100 may estimate the distance between tag 10505 and transceiverantennas 10504 by transmitting a signal to a frequency doubling circuitin tag 10505 and processing the returned frequency doubled signal.System 100 may include radio section 10501 that transmits a widebandwidth digitally modulated signal to a wide band antenna thatreflects some portion back to the transceiver at double the frequency.The returned signal contains with both digital modulation and afrequency offset. The distance between antennas 10504 a, 10504 b and tag10505 is typically proportional to the frequency offset. The frequencyoffset is converted to a difference frequency by mixer 10506 and thesecond harmonic of transmitted digitally modulated signal.

The antenna for tag 10505 may incorporate antenna 9600, antenna 9900, orantenna 10200 as discussed above. However, antennas 10504 a, 10504 b maycomprise a planar inverted F antenna with some embodiments. Antennas10504 a, 10504 b may address different considerations because antennas10504 a, 10504 b are typically located in a player's garment or shoehaving a different antenna environment than that of a ball. For example,the proximity (typically varying) of a player's shoe to the ground mayhave a substantial effect on the electrical characteristics of antennas10504 a, 10504 b.

The link budget is typically a calculation of the range using parameterssuch as the frequency of operation, RF path loss, bandwidths, noisefigures, transmitted power, antenna gains and propagation models. Thelink budget is used to determine the required radio specifications tomeet desired range or to determine the range as a result of selectedsystem performance parameters. FIG. 106 summarizes the link budgetcalculations showing the SNR with distance for exemplary simulationresults.

Radio section 10501 may be controlled through firmware executing on ahighly integrated system on chip based microcontroller component 10502.For example, microcontroller 10502 may comprise a microcontroller fromthe MSP430 family with 256 kB of flash memory, 16 kB of RAM memory(which may be included as part of data storage not explicitly shown),and built in analog-digital converter 10514. Microcontroller 10502controls radio section 10501 and stores the data that represents thedistance between the tag and the transceiver antennas. Radio section10501 may be controlled through a system packet interface (SPI)interface and general purpose input/outputs (GPIOs). Microcontroller10502 may also control a lithium ion battery charging circuit. Arechargeable battery may be selected due to the current consumption andfor the lightweight, compact form factor available through lithiumpolymer cells. Radio section 10501 includes transmitter and receiversections. The transmitter includes a phase lock loop (PLL) synthesizer,transmit amplifier and several filters. The receiver includes a lownoise amplifier 10515, harmonic mixer 10506, PLL synthesizer based localoscillator 10507, IF section 10513, and filters 10511 and 10512.

The processed signal from IF section 10513 may be digitized byanalog-digital converter 10514, and the resulting frequency differenceinformation (as will be further discussed) may be processed bycontroller 10502 to estimate the distance between the player and theball.

While radio section 10501 combines both transmitting and receivingoperations, some embodiments may separate transmitting operation fromreceiving operation. In such a case, separate antennas may be used fortransmitting (antenna 10504 a) and for receiving (antenna 10504 b) asshown in FIG. 105 rather than using a common antenna.

The distance may be estimated through receiving a signal relayed throughthe frequency doubling tag 10505. With some embodiments, a transmissionis sent from the transceiver when the microcontroller programs A PLLsynthesizer through a series of frequency tunes that represent aGaussian frequency-shift keying (GFSK) modulation. The transmittedsignal has wideband GFSK modulation, is centered at 2442 MHz, has anapproximate bandwidth of 80 MHz, and an output power of approximately 10mW. For example, variable control oscillator (VCO) 10507 sweeps thetransmitted frequency from 2402 MHz to 2483 MHz during a time duration(e.g., several hundred microseconds) to generate a sweep signal that maybe referred as a chirp.

With a multi-player environment, it is typically desirable to avoid theoverlapping of chirps generated by different transceivers, where eachtransceiver is associated with a different player. If chirps fordifferent players overlap, the resulting return signals may interactwith each other, causing an error in determining the correct differencefrequency and consequently the estimated distance to the ball.Embodiments of the invention may use different approaches for collisionavoidance, including randomizing generation of chirps to reduce theprobability of collisions.

The radiated transmission is relayed through passive frequency doublingtag 10505. The second harmonic of the signal is received and centered at4884 MHz. Consequently, tag 10505 doubles the transmitted frequency ofthe sweep signal from radio section 10501.

With embodiments of the invention, radio section 10501 transmits thesweep signal over transmission path 10551 to tag 10505 andsimultaneously receives a signal from tag 10505 over receive path 10552(i.e., full duplex operation) in contrast to traditional systems inwhich a complete chirp must be transmitted before processing thereturned signal. With the exemplary embodiment shown in FIG. 105, thesweep signal is transmitted through amplifier 10510 while the returnedsignal is simultaneously received.

The received signal at radio section 10501 is amplified by low noiseamplifier (LNA) 10515 and filtered by filter 10516 and filter 10517. Theamplified signal is down converted to the baseband and IF circuitthrough the multiplication in the sub-harmonic mixer with the PLLsynthesizer output. With some embodiments, the IF circuit has abandwidth of 200-50000 Hz with a high-pass characteristic starting at200 Hz. and comprises four very lower power OPAMPs in a 4th order lowpass Butterworth Sallen Key configuration with an approximate gain of 57dB.

The volumetric estimate of the layout based on block diagram 10500 maybe calculated assuming microvias and compact component selections. Thelayout of block diagram 10500 may include some large connectors forloading firmware, extracting data, and debugging that may be needed in afinal version and may not be included in the volumetric estimate.Exemplary dimensions for the PCB are approximately 1 by 1 by 0.3 inches.If connectors are included, the interior volume may be ⅔ higher. Itemsnot included in the volumetric estimate are the antenna and theenclosure. The rechargeable battery may be approximately 1 by 0.5 by 0.3inches.

FIG. 107 shows flow chart 10700 that may be performed by system 10500 asshown in FIG. 105 in accordance with embodiments of the invention. Withsome embodiments, VCO 10507 independently changes the frequency of thetransmitted signal in a predetermined series of frequency changes onceinitiated by controller 10502. Embodiments of the invention may utilizedifferent frequency tuning characteristics including a linear,exponential, or a Gaussian function. However, with some embodiments,controller 10502 may directly control VCO 10507 to generate thetransmitted frequency.

Some or all blocks 10701-10706 may be performed sequentially or may beperformed in parallel.

Controller 10502 may instruct VCO 10507 to start the chirp at block10701. As previously discussed, the generation of the chirp may berandomized to reduce the probability that a chirp is being generated bya transceiver associated with a different player in a multi-playerenvironment. Radio section 10501 consequently transmits the sweep signalto tag 10505 at block 10702 and simultaneously receives the returnedsignal from tag 10505 at block 10703. Because of the propagation timebetween radio section 10501 and tag 10505, the doubled transmittedfrequency is different from the received frequency.

At block 10704 radio section 10501 compares the frequency of thereturned signal from tag 10505 with the current doubled sweep frequencyto obtain a frequency difference.

Execution of blocks 10702-10704 continues during the time duration thatthe chirp occurs as determined by block 10705. When the sweep has beencompeted, the frequency difference information is used to determine thedistance (proximity) between the player and the ball at block 10706based on EQs. 1-3 as will be discussed. For example, the average valueof the frequency difference over the measurement time duration may beused to estimate the distance between the player (corresponding to radiosection 10501) and the ball (corresponding to tag 10505). A plurality tomeasurements of the frequency difference may be obtained. When thevariability of the frequency difference measurements is greater than apredetermined threshold, process 10700 may determine that the proximityestimate is not acceptable and may generate another chirp to repeatprocess 10700.

Once the chirp has been sent and the proximity estimated, process 10700may be repeated to update the estimated proximity.

The frequency change may be performed in a continuous or a discretebasis. For example, the transmitted frequency may be linearly increasedover a predetermined time duration using the following relationship:

f _(transmitted)(t)=f ₀ +αt  (EQ. 1)

where f₀ is the initial frequency and α is the change of frequencyduring the predetermined time duration. Tag 10505 returns a receivedsignal in which the received frequency of transmitted signal is doubled.Accounting for the one-way propagation time (T) between antennas 10504and 10505:

f _(received)(t)=2f ₀+α(t−2T)  (EQ. 2)

The frequency of the transmitted signal is doubled (f_(2,t)(t) whichrepresents the second harmonic of the currently transmitted signal) andis mixed with the received signal (corresponding to EQ. 2) by mixer10506 to obtain a frequency difference:

f _(2,t)(t)−f _(received)(t)=4αT  (EQ. 3)

While EQs. 1-3 model a continuous process, some embodiments may changethe transmitted frequency as discrete process, where the sweep(transmitted) frequency is incremented Δ every time incrementt_(i+1)−t_(i). Rather than determining the frequency difference usingEQ. 3, some embodiments may use a predetermined lookup table that isrepresented by Table 1, where data representing Table 1 is stored inmemory. Consequently, controller 10502 may determine the frequencydifference and use the value to lookup up the propagation time T. Thedistance between the player and the ball may then be determined from thedetermined propagation time.

TABLE 1 PROPAGATION TIME AS A FUNCTION OF FREQUENCY DIFFERENCE PROP.FREQUENCY FREQUENCY FREQUENCY FREQUENCY TIME DIFF = Δ₁ DIFF = Δ₂ DIFF =Δ₃ DIFF = Δ₄ t₁ T₁ t₂ T₁ T₂ t₃ T₁ T₂ T₃ t₄ T₁ T₂ T₃ T₄

With some embodiments, rather than obtaining the propagation time fromthe frequency difference, the distance between the tag (corresponding tothe ball) and the transceiver (corresponding to the player) may bevaried by experimentation. The corresponding frequency difference may beobserved without specific knowledge of the multipath characteristicsbetween the transceiver and the tag. The experimental information maythen be later used when monitoring player performance during athleticactivities.

IV. Conclusion

The present invention is described above and in the accompanyingdrawings with reference to a variety of example structures, features,elements, and combinations of structures, features, and elements. Thepurpose served by the disclosure, however, is to provide examples of thevarious features and concepts related to the invention, not to limit thescope of the invention. One skilled in the relevant art will recognizethat numerous variations and modifications may be made to theembodiments described above without departing from the scope of thepresent invention, as defined by the appended claims. For example, thevarious features and concepts described above in conjunction with FIGS.1-107 may be used individually and/or in any combination orsub-combination without departing from this invention.

What is claimed is: 1.-20. (canceled)
 21. An athletic monitoring systemcomprising: a transceiver configured to communicate with a plurality ofbody-worn athletic devices comprising at least a first athletic deviceand a second athletic device, each of the plurality of athletic devicesrespectively configured to be uniquely associated and releasablyattached to a corresponding plurality of players during performance ofan athletic activity; a processor; a display unit configured to displayathletic information; and a non-transitory computer-readable mediumcomprising computer-executable instructions that when executed by theprocessor perform at least: receive, in real-time during an athleticactivity, athletic motion data collected from a sensor of the firstathletic device while releasably attached to a first player and athleticmotion data from a sensor of the second athletic device while releasablyattached to the second player; process, with the processor, the athleticmotion data from the first athletic device to create a first measurementof a first athletic metric for the first athlete during the athleticactivity; process, with the processor, the athletic motion data from thesecond athletic device to create a second measurement of the firstathletic metric for the second athletic activity; deriving, with theprocessor, during the athletic activity, that the first measurementmeets a threshold criteria that the second measurement does not meet;determine, with the processor, an identity of the first player that isuniquely associated with the first athletic device; and display, on thedisplay unit during performance of the athletic activity, that isviewable to a plurality of individuals, the first measurement of thefirst athletic metric and the identity of the first player uniquelyassociated with the first athletic device.
 22. The athletic monitoringsystem of claim 21, wherein the non-transitory computer-readable mediumcomprises computer-executable instructions that when executed by aprocessor cause the processor to perform at least: identify at least aportion of the plurality of athletic devices, including the firstathletic device, as being uniquely associated with players on a firstsporting team based, at least in part, the transceivers of the at leasta portion of the plurality of athletic devices being within a proximitythreshold.
 23. The athletic monitoring system of claim 21, wherein thefirst measurement is an average vertical height measurement determinedfrom vertical height measurements obtained for predefined period oftime.
 24. The athletic monitoring system of claim 23, wherein thepredefined period of time is a timed duration of a sporting event. 25.The athletic monitoring system of claim 24, wherein the timed durationof the sporting event is a quarter of a basketball game.
 26. Theathletic monitoring system of claim 21, wherein the non-transitorycomputer-readable medium comprises computer-executable instructions thatwhen executed by a processor cause the athletic monitoring device toperform at least: receive electronic information corresponding to aninteraction between a radio tag of a ball and athletic metric data fromthe second athletic device of the plurality of body-worn devices isindicative of a controlled behavior; identify, with the processor, theidentity of the second player uniquely associated with the secondathletic device; and simultaneously displaying on a display unit theidentity of the second player with an athletic metric data value that isdifferent from the first athletic metric.
 27. The athletic monitoringsystem of claim 26, wherein one of the non-transitory computer-readablemedium comprises computer-executable instructions that when executed bya processor cause the computer device to perform at least: determiningthat the second player is in possession of the ball.
 28. The athleticmonitoring system of claim 27, wherein the determining the second playeris in possession is based on, at least in part, the indication of thecontrolled behavior.
 29. The athletic monitoring system of claim 21,wherein the non-transitory computer-readable medium comprisescomputer-executable instructions that when executed by the processorcause the processor to perform at least: identify a first portion of theplurality of athletic devices, including the first athletic device, asbeing uniquely associated with players on a first sporting team; andidentify a second portion of the plurality of athletic devices,including the second athletic device, as being uniquely associated withplayers on a second sporting team; process, with the processor, aplurality of measurements for the first metric from the second portionto determine that the second measurement from the second athletic deviceis a winning measurement; and display on the display unit duringperformance of the athletic activity, that is viewable to a plurality ofindividuals, the winning measurement for the second plurality ofathletic devices with the identity of the second athlete, wherein thedisplaying is simultaneous with the displaying of the first measurementof the first athletic metric and the identity of the first athlete. 30.The athletic monitoring system of claim 29, wherein the non-transitorycomputer-readable medium comprises computer-executable instructions thatwhen executed by the processor cause the processor to perform at least:determine that the second athletic device transmitted a measurement of asecond athletic metric that is characterized by a vertical heightmeasurement that is higher than vertical height measurements than theother athletic devices within the second portion of the plurality ofathletic devices; and display, simultaneously with a first verticalheight measurement from the first athletic device on the display unitduring the performance of the athletic activity, a second verticalheight measurement from the second athletic metric and an identity ofthe first and second players which are uniquely associated with thefirst and second athletic devices, respectively.
 31. Acomputer-implemented method comprising: processing, in real-time with aprocessor, athletic movement data from a plurality of body-worn athleticdevices that are each respectively configured to be uniquely associatedand attached to a corresponding plurality of players during performanceof an athletic activity; wherein the plurality of body-worn athleticdevices comprise a first and a second body-worn athletic device that areuniquely associated to a first player and a second player, respectively,amongst the plurality of players; wherein the processing comprisescalculating on the first athletic device, athletic metric data fromathletic motion data captured by a sensor on the first body-wornathletic device and calculating on the second athletic device, athleticmetric data from athletic motion data captured by a sensor on the secondbody-worn athletic device, the athletic metric data comprising aplurality of measurements; during the simultaneous performance of theathletic activity by the first player and the second player, displayingon an on-board display unit of the first athletic device, a firstmeasurement of the plurality of measurements from the first player and afirst measurement of the plurality of measurements from the secondplayer; transmitting, via a transceiver of each plurality of athleticdevices during the athletic activity, at least a portion of theplurality of measurements of at least the first player and the secondplayer of the respective athletic devices, to a central computer device;determining that a first measurement of a first athletic metric of thefirst player is higher than a second measurements of the first athleticmetric of the second player; and displaying, during performance of theathletic activity, on a second display unit that is viewable to aplurality of individuals, the first measurement and identity of thefirst player uniquely associated with the first athletic device.
 32. Themethod of claim 31, further comprising: identifying at least a portionof the plurality of athletic devices as being uniquely associated withplayers on a first sporting team.
 33. The method of claim 31, whereinthe first measurement is an average vertical height measurementdetermined from a plurality of vertical height measurements obtained forpredefined period of time.
 34. The method of claim 33, wherein thepredefined period of time is a timed duration of a sporting event. 35.The method of claim 34, wherein the timed duration of the sporting eventis a quarter of a basketball game.
 36. The method of claim 31, furthercomprising: receiving electronic information corresponding to aninteraction between a radio tag of a ball and athletic metric data fromthe second athletic device of the plurality of body-worn athleticdevices is indicative of a controlled behavior; identifying, with aprocessor, the identity of the second player uniquely associated withthe second athletic device; and simultaneously displaying on a displayunit external to both the first and the second athletic devices, theidentity of the second player with an athletic metric data value of thesecond player collected during the performance of the athletic event.37. The method of claim 36, further comprising: determining that thesecond player is in possession of the ball.
 38. The method of claim 37,wherein the determining the second player is in possession is based on,at least in part, the indication of the controlled behavior.
 39. Themethod of claim 31, further comprising: identifying a first portion ofthe plurality of athletic devices as being uniquely associated withplayers on a first sporting team; identifying a second portion of theplurality of athletic devices as being uniquely associated with playerson a second sporting team; simultaneously displaying the first verticalheight measurement and a second height vertical measurement from asecond athletic device within the second portion of the plurality ofathletic devices.
 40. The method of claim 39, further comprising:determining that the second athletic device transmitted a secondvertical height measurement that is characterized by being higher thanvertical height measurements than the remaining athletic devices withinthe second portion of the plurality of athletic devices.